CONTENTS
PAGE NUMBER
Biology
B1. Characteristics of living organisms
B2. Cells
B3. Biological molecules
B4. Enzymes
B5. Plant nutrition
B6. Animal nutrition
B7. Transport
B8. Gas exchange and respiration
B9. Coordination and response
B10. Reproduction
B11. Organisms and their environment
B12. Human influences on ecosystems
01
01
05
07
09
11
16
21
25
27
34
36
Chemistry
C1. The particulate nature of matter
C2. Experimental techniques
C3. Atoms, elements and compounds
C4. Stoichiometry
C5. Electricity and chemistry
C6. Energy changes in chemical reactions
C7. Chemical reactions
C8. Acids, bases and salts
C9. The Periodic Table
C10. Metals
C11. Air and water
C12. Organic chemistry
38
40
44
51
53
55
56
60
67
71
75
77
Physics
P1. Motion
P2. Work, energy and power
P3. Thermal Physics
P4. Properties of waves, including light and sound
P5. Electrical quantities
P6. Electric circuits
82
94
102
110
120
124
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Characteristics of living organisms
Describing the characteristics of living organisms by defining the following terms
Movement: movement refers to an action by an organism causing a change of position or
place.
Reproduction: reproduction refers to processes that make more of the same kind of organism.
Sensitivity: sensitivity refers to the ability to detect and respond to changes in the
environment.
Growth: growth refers to the permanent increase in size and dry mass by an increase in the
number of cells, cell size, or both.
Respiration: respiration refers to the chemical reactions in cells that break down nutrient
molecules and release energy.
Excretion: excretion refers to removal, from organisms, of toxic materials and substances in
excess of requirements. These toxic materials are waste products of metabolism and
substances taken in excess.
Nutrition: nutrition refers to taking in of materials for energy, growth and development.
The seven characteristics could be memorized by the term “MRS. GREN” using the first
letters of each characteristic mentioned above.
Cells
Cell structure
Stating that living things are made of cells
Living organisms are made of cells. Cells are very small; hence, they can only be seen under
a microscope. We have two types of cells namely plant and animal cells.
Describing and comparing the structure of a plant and animal cell.
Note similarities: both contain a cell membrane, cytoplasm and nucleus
Note differences: in addition, a plant cell contains a cell wall, chloroplasts, and a sap vacuole
Page 1 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Stating the functions of the structures found in cells
1. Cell wall: This is a non-living thick rigid layer surrounding the cell. It is made of
cellulose, and it gives the cell its shape (angular, rectangular or rounded) and prevents
it from bursting. It also allows the plant to support itself. The cell wall is permeable
i.e. it allows all substances to move into or out of the cell. Only the semi-permeable
membrane will allow or dis-allow entry or exit of some substances into the cell.
2. Cell membrane: This is a partially permeable membrane. It controls the movement of
substances into and out of the cell.
3. Cytoplasm: This is a jelly like substance made up of mostly water and structures.
Metabolic reactions occur in the cytoplasm.
4. Chloroplasts: These are green discs which contain chlorophyll (which is a green
pigment that traps sunlight for photosynthesis).
5. Nucleus: Controls all activities of the cell.
6. Sap vacuole: A vacuole is a large room in the center of the cell. It contains cell sap.
The cell sap stores dissolved sugars, mineral salts and amino acids. It also controls the
movement of water in and out of the cell.
Page 2 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Relating the structure of certain cells to their functions:
Type of cell
Ciliated cells
Where it is found
Lining the trachea and bronchi
Root hair cells
Xylem vessels
Near the ends of plant roots
In stems, roots and leaves of plants
Palisade mesophyll
cells
Nerve cells
Beneath the epidermis of a leaf
Red blood cells
Sperm and egg cells
In the blood of mammals
Sperm in testes and egg cells in ovaries
Throughout the bodies of animals
Function
Move mucus upwards to the back
of the throat
Absorb water and mineral salts
Transport water and mineral salts;
help in support
Photosynthesis
Transmit information in the form of
electrical impulses
Transport oxygen
Fuse together to produce a zygote
Ciliated Cells:
Ciliated cells have cilia whose function is to move the mucus up the trachea and bronchi to
the throat. The mucus traps bacteria and dust particles. When it reaches the throat, mucus is
swallowed to the stomach where the acid kills the bacteria.
Root Hair Cells:
Their function is to absorb water and minerals from the soil. They are adapted by 3 ways.
One, they have a large surface area for more water intake. Two, they have a large number of
mitochondria for respiration to become more active. Three, they have a concentrated vacuole
to support the absorption of water by osmosis.
Palisade mesophyll cells:
Consist of one or two layers of closely-packed, long and cylindrical cells containing
chloroplasts. Their function is to facilitate photosynthesis. They contain numerous
chloroplasts to allow maximum absorption of light.
Leaf structure
showing one layer of
palisade mesophyll
cells
Page 3 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Sperm cells have
 a tail – to help them swim
 a head which has digestive enzymes to breakdown the outer membrane of the ovum to
allow fertilization to occur
 a middle piece with numerous mitochondria to provide energy for the sperm to swim
(this point is not in the syllabus though)
An egg cell
Egg cells (ova) possess a yolk which acts as a food store. The spherical shape of ova allows
cilia lining the oviducts to easily move the ovum so that it can meet sperm and be fertilized
by it.
Calculating magnification and size of biological specimens using millimetres as units
Magnification =
𝑠𝑖𝑧𝑒 𝑜𝑓 𝑑𝑟𝑎𝑤𝑖𝑛𝑔
𝑠𝑖𝑧𝑒 𝑜𝑓 𝑟𝑒𝑎𝑙 𝑜𝑏𝑗𝑒𝑐𝑡
in mm
Movement in and out of cells
Defining diffusion
Diffusion is the net movement of particles from a region of higher concentration to a region
of lower concentration down a concentration gradient, as a result of their random movement.
Substances move into and out of cells by diffusion through the cell membrane. Water diffuses
through partially permeable membranes by osmosis.
Defining osmosis
Osmosis is the net movement of water molecules from a region of higher water potential
(dilute solution) to a region of lower water potential (concentrated solution), through a
partially permeable membrane. Water moves in and out of cells by osmosis through the cell
membrane. Water also enters the roots by osmosis.
Page 4 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Investigating and describing the effects of immersing of plant tissues in solutions of
different concentrations
Water potential is a measure of the tendency of water molecules to move from one region to
another.
Dilute solutions have a higher water potential than concentrated solutions. Pure water has the
highest water potential. Water molecules that dissolve solutes are bound to the solute
particles. A dilute solution thus has a lot of unbound water molecules, giving it a higher water
potential than a concentrated solution.
Immersing plant tissues in concentrated solutions of salts make the tissues smaller (flaccid)
due to the movement of water molecules out of the tissues and into the concentrated solution.
Immersing plant tissues in pure water can make the tissues bigger (turgid) due to movement
of water molecules from the pure water and into the tissues. Cell walls in plant cells prevent
them from bursting. Absence of cell walls in animal cells can result in bursting due to too
much water uptake by cells.
Small dots are
water and large
dots are solute
particles.
Biological molecules
Listing the chemical elements that make up:
1. Carbohydrates: made up of carbon, hydrogen and oxygen only.
2. Fats: made up of carbon, hydrogen and oxygen (less oxygen than in carbohydrates).
3. Proteins: made up of carbon, hydrogen, oxygen and nitrogen. They sometimes contain
sulphur and phosphorus.
Large molecules are made from smaller molecules: e.g.
1. Starch and glycogen are made from glucose
2. Proteins are made from amino acids
3. Fats and oils are made from fatty acids and glycerol
Page 5 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Food tests
Test for starch
1. The test for starch is called the Iodine test. Iodine is added to the sample and the colour
change (if any) is observed.
2. Procedure: Add a few drops of iodine solution (which is brown) to the sample. If the
sample contains starch, it will turn blue-black in colour.
Test for reducing sugars
1. The test for reducing sugars is known as the
Benedict’s test.
2. Reducing sugars are glucose, fructose, galactose,
maltose and lactose. Sucrose is not a reducing sugar.
3. Procedure: Add Benedict’s solution to the sample
and mix the contents thoroughly. Heat the mixture in
a boiling water bath for 5 minutes.
4. The colour of the solution changes from blue to
green to yellow to orange to brick-red if a reducing
sugar is present.
Test for proteins
5. Both test tubes on the left contain reducing sugar,
however, the one on the right side contains more than
the one on the left.
1. The test for proteins is known as the Biuret test.
2. The main reagents are aqueous sodium hydroxide (potassium hydroxide can also be used)
and copper (II) sulfate. A ready mixed reagent of the two chemicals called Biuret reagent can
also be used.
3. Procedure: First add copper sulfate solution to a solution of the food sample, followed by
either sodium or potassium hydroxide solution.
4. If proteins are present, a colour change from blue to purple will be observed.
Test for fats and oils
1. The test for fats is known as the ethanol emulsion test.
2. Fats in the sample are dissolved by adding ethanol. Water is then added to the ethanolic
mixture. Since fats do not dissolve in water, they form a cloudy white emulsion.
Page 6 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Nutrient
Starch
Reducing sugars
Proteins
Fats
Test
Iodine solution
Benedict’s solution
Biuret reagent
Ethanol and water
Original colour
Brown
Blue
Blue
------------
Positive result
Blue/black
Brick red
Purple
Cloudy
Negative result
Brown
Blue
Blue
Clear
Water:
About 70% of your weight is water. Water is an essential nutrient. The functions of water
include:
• As a solvent which dissolves reactants of metabolic reactions.
• As a component of blood plasma in which red blood cells, nutrients, hormones and other
materials are carried in.
• It helps in lowering the body temperature in hot conditions in the form of sweat on the skin.
The sweat evaporates using heat energy from the body, thus lowering the temperature.
Enzymes
Enzymes are proteins that function as biological catalysts. Catalysts speed up the rate of
chemical reactions without being altered in the reaction.
Explaining enzyme action
1. Enzymes are biological catalysts that speed up the rate of chemical reactions without being
altered in the reaction. They are made of proteins.
2. They are substrate-specific. Substrates are the reactants that an enzyme acts on e.g.
amylase can only digest starch and not cellulose even though they are both polymers of
glucose.
Enzymes are believed to function using the lock and key hypothesis.
1. An active site is the region on an enzyme molecule that the substrate binds to. It is usually
a groove on the surface of the enzyme. Only the correct substrate is able to fit into the active
site.
2. Enzyme action begins when the substrate molecule binds to the active site of the enzyme to
form an enzyme-substrate complex.
3. The substrate is then converted into product molecules.
4. The product molecules depart from the active site, leaving the enzyme free to catalyse
another reaction.
Page 7 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Investigating and describing the effect of changes in temperature and pH on enzyme
activity
Effect of temperature
1. At low temperatures, the rate of a reaction is very low because substrate particles are
moving too slowly to react. Substrate and enzyme molecules have little kinetic energy; hence
the frequency of collision is low.
2. As the temperature increases, the rate of enzyme activity increases. Substrate and enzyme
molecules gain more kinetic energy; hence the frequency of collisions between substrate
molecules and active sites of enzymes increases.
3. Enzyme activity increases up to an optimum temperature, beyond which it starts
decreasing. Enzymes which are found in the human body usually work best at about 37 °C.
4. As the temperature increases beyond the optimum temperature, enzyme activity drops
because enzymes are made of proteins, which are denatured at high temperatures.
5. At extremely high temperatures, the enzyme is completely denatured and the rate of
reaction drops to zero.
Page 8 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
1. Enzyme activity is highest at the optimum pH of
the enzyme.
Effect of pH
2. As the pH increases or decreases from the
optimum, enzyme activity sharply decreases. This
is because the shape of the active site is changed as
the enzyme is denatured. When this happens, the
active site no longer fits the substrate, so the
enzyme can no longer catalyse its reaction.
3. At extreme pH levels, the enzyme is completely
denatured and the rate of reaction drops to zero.
4. The optimum pH for each enzyme differs. For
example, pepsin works best under the acidic
conditions in the stomach, while intestinal
enzymes work best under alkaline conditions.
Plant nutrition
Photosynthesis is the process by which plants manufacture carbohydrates from raw materials
using energy from light.
The word equation for photosynthesis is:
carbon dioxide + water → glucose + oxygen, in the presence of light and chlorophyll
The balanced chemical equation for photosynthesis is:
Chlorophyll converts light energy into chemical energy in molecules. The chemical energy is
then used for the synthesis of carbohydrates.
The subsequent use and storage of the carbohydrates made in photosynthesis
Glucose, the product of photosynthesis is the most important food of the plant. Plants make
other nutrients from glucose. Glucose is transported to other parts of the plant as sucrose e.g
to the roots, where it can be converted back to glucose for respiration, and part of it into
starch for storage (this is the case with potatoes and sweet potatoes). Growing cells make
cellulose for cell walls from sucrose. Fruits use the sucrose to make the attractive scent and
tasty nectar to attract insects.
Importance of photosynthesis
 Converts light energy from the Sun to chemical energy in the form of glucose, which
can then be used by plants and animals.
Page 9 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
 In the day, the leaf produces more glucose than can be removed. The excess glucose
is then converted into starch and stored in the leaf, or converted to sucrose and
transported to other parts of the plant via the phloem.
 At night, starch stored in the leaf is then converted to glucose for respiration.
 Excess glucose is converted to sucrose before being transported out of the leaf for use
by other parts of the plant, or converted to starch for storage in the various storage
organs.
 The stored starch can be used to make cellulose.
 Photosynthesis ensures that living things have a constant supply of oxygen.
Factors affecting photosynthesis
The rate of photosynthesis increases as the amount of water, concentration of carbon dioxide,
temperature and light intensity increase. Submerged aquatic plants can have reduced
photosynthesis due to events like eutrophication which cause growth of algae on the surface
of water bodies resulting in reduced light intensity reaching the submerged aquatic plants.
Leaf structure
You should be able to identify chloroplasts, cuticle, guard cells and stomata, upper and lower
epidermis, palisade mesophyll, spongy mesophyll, vascular bundles, xylem and phloem in
leaves of a dicotyledonous plant.
Features of leaves that enable it to perform its functions
Palisade mesophyll cells for photosynthesis:
Their function is to facilitate photosynthesis. They contain numerous chloroplasts to allow
maximum absorption of light. Their chloroplasts are arranged alongside the cell wall and are
Page 10 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
most abundant on the side facing the sunlight. The position of the chloroplasts actually
changes to ensure efficient absorption of sunlight.
Stomata, spongy mesophyll cells and guardcells for gas exchange:
Spongy mesophyll cells have air spaces to allow for fast diffusion of carbon dioxide, which
enters the leaf through the stomata, to all photosynthetic cells.
Guard cells are bean-shaped, chloroplast-containing cells located in the lower epidermis.
They control the opening and closing of the stoma (plural: stomata), the gap between the
guard cells. The stomata allow carbon dioxide to diffuse in, oxygen to diffuse out and water
vapour to escape.
Plants open their stomata during the day for carbon dioxide intake and close their stomata
during the night to minimize water loss through transpiration. Guard cells control the opening
and closing of stomata through regulation of water potential within themselves.
Xylem for transport and support
The xylem transports water and mineral salts from the roots to the leaves. A xylem vessel is
made up of hollow tubes joined end to end forming a long drain pipe which runs from the
roots to the stem.
The xylem also adds mechanical support to the plant since its walls are made of strong
cellulose and lignin
Phloem for transport
The function of the phloem is to transport sugars and amino acids from the leaves to other
parts of the plant.
Describing the importance of nitrate ions for making amino acids and magnesium ions
for making chlorophyll
• Mg2+ (Magnesium ions): they are important for the production of the green pigment
chlorophyll. Lack of it results in lack of photosynthesis and yellowing between the veins of
leaves
• Nitrates: these are the sources of nitrogen; they are required to make amino acids and
proteins. Lack of it results in weak growth and yellowing of the leaves. Both mineral ions are
absorbed from the soil.
Animal nutrition
A balanced diet: is a perfect diet which contains all of the nutrients in reasonable
proportions.
Page 11 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Nutrient
Source
Carbohydrates
Fruits, Honey, sugar,
Bread, Potatoes, Pasta,
sadza/maize meal etc
Fats
Butter, cooking oil, red
meat
Proteins
Milk, meat, eggs
Vitamin C
Citrus fruits e.g oranges
and lemons (vitamin C
is damaged by cooking)
Vitamin D
Butter, egg yolk,
exposure to sunlight
Dietary importance
 Energy resource, essential in respiration
to release energy.
 Also used in creating cellulose, the
substance that makes up cell walls of
plant cells.
 Synthesis of membranes.
 Solvent for fat soluble vitamins.
 Storage of energy.
 Insulating material.
 For growth and repair of worn out
tissues.
 Synthesis of enzymes and hormones.
 Formation of antibodies.
 Essential for the formation of collagen, a
protein that functions as a cementing
layer between cells.
 Increases immunity.
 Promotes absorption of calcium from
small intestines and its deposition in
bones.
Mineral salts
Calcium
Milk, cheese, eggs
 Making bones and teeth.
 Normal functioning of muscles and blood
clotting process.
Iron
Red meat especially
liver, green leafy
vegetables
 Needed for the formation of the red
pigment haemoglobin, which is essential
for the transportation of oxygen around
the body in red blood cells.
Fibre/roughage
Fruits and vegetables
(cellulose from
roughage is not
digested/absorbed.
Roughage is from cell
walls of plant cells.)
 Provide bulk to undigested matter and
promote peristalsis. The process of
pushing the food through the gut is called
peristalsis, without roughage peristalsis is
very slow and weak
Water
Water, juices. (70% of
the body is water)
 Medium/solvent for various enzymatic
reactions.
 Main component of blood plasma.
 Main component of sweat. Sweat lowers
body temperature in hot conditions by
absorbing heat from the body. This leads
to the evaporation of the sweat.
Page 12 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
How age, gender and activity affect the dietary needs of humans including during
pregnancy and whilst breast-feeding.
Pregnant Women:
The diet of a pregnant woman needs to be very rich in certain nutrients because she is not
only feeding herself; she is feeding her baby as well. In order for the fetus to develop well, it
needs extra protein, iron, calcium and vitamin D. Proteins are used to develop the tissues of
the fetus, iron is used to make haemoglobin, while calcium and vitamin D are used to develop
the baby’s bones.
Breast-Feeding Women (Lactation):
Lactation means the production of breast milk. After pregnancy, the mother breast-feeds the
baby for about 6 months or more. Breast milk needs to be high in proteins, calcium, and
vitamins to guarantee the healthy growth of the infant.
Growing Children (Passing Puberty):
At some point, each child gets a growth spurt. This is a very high growth rate that increases
the child’s size and mass in a short period of time. A growing child’s diet needs extra proteins
to develop cells and enzymes because their metabolic rate is higher. They also need calcium
and vitamin D to develop bones, and iron to make haemoglobin.
Some other considerations:
Men need more energy than women. Teenagers need more energy, proteins and calcium than
adults. Blue collar (industrial) workers need more energy than white collar (office) workers.
Effects of malnutrition in relation to starvation, obesity, constipation, coronary heart
disease and scurvy
Malnutrition is eating inadequate proportions of food. It is a consequence of an unbalanced
diet. An unbalanced diet is rich in some nutrients and low in others, or even lacking. There
are lots of effects of malnutrition such as starvation, obesity or deficiency diseases.
Starvation is an effect of malnutrition. In the case of starvation, the body tends to feed on its
own self. When the glucose level is decreased in the body, the liver breaks down fats to
respire for energy, when the body is out of fats, it starts respiring proteins from the muscles to
release energy, eventually the body ends up looking like a skeleton. Starvation is usually
present in countries with famines, which are caused by poverty, large populations, low
amounts of food, unsuitable climates and lack of money.
Obesity is the opposite of starvation. It is eating too much of every nutrient, especially
carbohydrates and fats. Obesity doesn’t strike alone; it brings with it several other diseases
such as high blood pressure, cardiac diseases, diabetes, stress on joints and bones, as well as
other psychological issues like low self-esteem and lack of confidence. To prevent obesity,
you have to control your carbohydrates and fats intake and exercise regularly.
Page 13 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Constipation: lack of fibre in the diet causes undigested matter to lack bulk. This results in
poor peristalsis, meaning that food stays too long in the large intestine. Since food stays
longer, lots of water is absorbed by the large intestine, resulting in dry hard stools.
Coronary heart disease: over consumption of carbohydrates and fats can lead to obesity. The
excess carbohydrates are converted into fats resulting in fatty deposits in organs and arteries.
These fatty deposits may lead to coronary heart diseases.
Scurvy is caused by a deficiency of vitamin C. Its symptoms include bleeding gums.
Explaining the causes and effects of vitamin D and iron deficiencies
Rickets (soft and deformed bones) is the deficiency disease of both vitamin D and calcium.
Bones are made of calcium, which vitamin D helps to deposit in the bones. If either calcium
or vitamin D is lacking in the diet, rickets is developed.
Anaemia is the deficiency disease of iron. The amount of haemoglobin decreases due to iron
deficiency. This causes short breath and tiredness.
The Alimentary canal
Ingestion is the taking of substances, e.g. food and drink, into the body through the mouth.
Digestion is the breakdown of large, insoluble food molecules into small, water soluble
molecules using mechanical and chemical processes.
Mechanical digestion is the breakdown of food into smaller pieces without chemical change
to the food molecules. The teeth are responsible for mechanical digestion.
Chemical digestion is the breakdown of large, insoluble molecules into small, soluble
molecules. Saliva, in the mouth, aids in chemical digestion. Chemical digestion is also found
in the alimentary canal.
Absorption is the movement of small food molecules and ions through the wall of the intestine
into the blood. It takes place in the small intestine.
Egestion is the passing out of food that has not been digested or absorbed, as faeces, through
the anus.
Identifying the main regions of the alimentary canal and associated organs, limited to
the mouth, salivary glands, oesophagus, stomach, small intestine, pancreas, liver, gall
bladder, large intestine and anus.
Page 14 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
The journey of food from the mouth to
the anus through the alimentary canal
includes 5 steps:
1. Ingestion: Taking in pieces of food
into the mouth
2. Digestion: The breakdown of
large, insoluble food particles into
smaller more soluble ones by
chemical and mechanical means.
3. Absorption: Taking the digested
food molecules from the
alimentary canal and into the
bloodstream
4. Assimilation: Movement of
digested food molecules into cells
where they are used e.g. to
release energy or growth etc.
5. Egestion: The elimination of
undigested food materials
through the anus
Digestion
Don’t confuse egestion with excretion;
excretion is to get rid of waste products of
metabolism.
Stating the significance of chemical digestion in the alimentary canal in producing
small, soluble molecules that can be absorbed
The significance of chemical digestion is that it produces small, soluble molecules that can be
absorbed.
Functions of enzymes in the human alimentary canal
1. Amylase breaks down starch to simpler sugars e.g. maltose
2. Protease breaks down protein to amino acids
3. lipase breaks down fats to fatty acids and glycerol
Stating where, in the alimentary canal, amylase, protease and lipase are secreted
1. amylase – for breaking down starch to simpler sugars, e.g. maltose, is secreted in the
mouth by salivary glands
2. protease – for digestion of proteins to amino acids, is secreted in the small intestines
3. lipase – for digesting fats into fatty acids and glycerol, is secreted in the small
intestines
Page 15 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Stating the functions of the hydrochloric acid in gastric juice
The hydrochloric acid in gastric (stomach) juices is for killing bacteria in food and giving an
acid pH for enzymes to work well.
Transport
Transport in plants
Stating the functions of xylem and phloem
Xylem
 conducts water and dissolved mineral salts from the roots to the stems and leaves
 provides mechanical support to the plant
Phloem
 transports manufactured food (sucrose and amino acids) from the leaves to other parts
of the plant e.g. the roots and flowers.
Transverse section of dicotyledonous stem
Transverse section of dicotyledonous root
For stems, the xylem is drawn as a hollow tube.
Root hair cells as seen under a light microscope, as well as their function
Root hairs
Root hair cells take in water and minerals
from the soil. Xylem vessels then take this
water to all parts of the plant.
Root
Page 16 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Stating the pathway taken by water through root, stem and leaf
 Water travels from the root to the stem and then to the leaf.
 The large surface area of root hairs increases the rate of the absorption of water.
 The pathway of water through parts of a plant can be investigated using stained water.
Transpiration
Transpiration is loss of water vapour from plant leaves by evaporation of water at the
surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata.
Factors which affect transpiration
 Light intensity – transpiration is greater in light than in darkness
 Temperature – as temperature increases, the rate of transpiration also increases
 Humidity of the atmosphere – transpiration is low when the level of humidity is high
Explaining the effects of variation of temperature, and humidity on transpiration rate
• Humidity: humidity means more water vapour in the air, which means water vapour has a
higher concentration in the atmosphere than inside the leaf, so transpiration will be much
slower because the diffusion of water vapour outside the leaf will be slow. The higher the
humidity the slower the transpiration. [Diffusion is the net movement of particles from a
region of higher concentration to a region of lower concentration down a concentration
gradient, as a result of their random movement].
• Temperature: when the temperature is high, molecules move faster and evaporate faster, so
transpiration rate increases. The higher the temperature the faster the transpiration.
Transport in mammals
The circulatory system is a system of blood vessels with a pump and valves to ensure oneway flow of blood.
Double circulation
The heart is a muscular organ which contracts to pump blood around the
body. It consists of four chambers – two upper chambers (atria) and two
lower chambers (ventricles). Both ventricles have thicker walls than
those of the atria. Humans have a double circulation system i.e
circulation to the lungs and circulation to the body tissues. There is a low
pressure circulation (between the heart and the lungs) and a high pressure
circulation (between the heart and the rest of body).
Advantages of double circulation
 Oxygenated and deoxygenated blood are separated
 Low pressure circulation prevents lung damage
 High pressure circulation ensures oxygenated blood reaches all
parts of the body
Page 17 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Cardiac 1. Muscles of the atria relax allowing blood to enter the heart. Atrioventricular valves
(bicuspid and tricuspid valves) open. Semilunar valves closed.
Cycle
2. Muscles of the atria contract whilst muscles of the ventricles remain relaxed.
Atrioventricular valves open. Semilunar valves closed. Blood is moved from atria to
ventricles.
3. Muscles of the atria relax whilst muscles of the ventricles contract. Atrioventricular
valves closed. Semilunar valves open. Blood moves out of the heart.
Page 18 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Naming blood vessels
Using the diagram above, you should be able to name
Blood vessels to and from the heart: vena cava, aorta, pulmonary artery and
pulmonary vein.
Blood vessels to and from the lungs: pulmonary artery and pulmonary vein.
Coronary heart disease
Coronary heart disease is caused by the blockage of coronary arteries. Possible risk factors
include diet high in fats or cholesterol, stress, smoking, genetic predisposition, age (risk
increases with age), and gender (affects males earlier than women).
Physical activity and pulse rate. Physical activity and heart rate.
A person’s pulse rate and heart rate are the same. Thus, physical activity increases both the
pulse and heart rate.
Structure and function of blood vessels
1. Arteries
Function: The function of arteries is to transport blood away from the heart to the lungs or
other parts of the body.
Structure: The blood in the arteries (excluding the pulmonary artery) always has a high
pressure. The lumen of arteries is very narrow. This adds to the pressure. Arteries have a
strong thick wall which is elastic and stretchable to withstand this high pressure.
Brief description of characteristics of arteries:
• Transport blood away from the heart
• Strong but stretchable walls
• Have a high blood pressure
• Narrow lumen.
2. Veins
Function: the function of veins is to transport blood from the body to the heart. The veins
always have low blood pressure because by the time the blood reaches the veins after touring
the body, it will have lost most of its pressure. This means that blood flows very slowly in the
veins. To prevent backflow, veins have valves.
Structure: since veins have low blood pressure, they don’t need strong, thick walls like the
arteries, instead they have thin and less elastic walls. Their lumen is much wider too.
Brief description of characteristics of veins:
• carry blood to the heart
• have low blood pressure
• have thin and less
elastic walls
• have wide lumen
• Valves present
Page 19 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Arteries
Blood flows away from the heart
Possess thick elastic walls
Carry oxygenated blood except pulmonary
artery
Do not possess valves except aorta
Arteries are usually deeper in the flesh than
veins
Pulse is detactable
Have narrow lumen
Veins
Blood flows towards the heart
Possess thin, not very elastic walls
Carry deoxygenated blood except pulmonary
vein
Possess valves to prevent back flow
Veins are nearer to the surface of the skin
Pulse is usually not detectable
Have wider lumen
3. Capillaries
Blood capillaries are the smallest blood vessels in our systems.
Function: capillaries collect nutrient filled and oxygenated
blood from the arteries and bring this blood closer to body
cells. Capillaries also link arteries with veins. When arteries
come near an organ or a tissue, they divide into arterioles, these
arterioles divide further into capillaries that go through the
tissue; this is when the exchange of oxygen and food nutrients
with carbon dioxide and waste products such as urea takes
place by diffusion.
Components of blood
Structure: Blood capillaries are very well adapted to their
function. They are one cell thick to reduce the diffusion
distance of materials thus promoting faster diffusion. They also
have pores in their walls between the cells, to allow the plasma
to get out of the blood and become tissue fluid.
Components of blood include red blood cells, white blood cells, platelets and blood plasma
Identifying red and white blood cells, as seen under the light microscope, on prepared
slides and in diagrams and photomicrographs
Diagram showing a red and a white blood cell
Microscopic view of
one white and many
red blood cells
Micrograph of red blood
cells
Page 20 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Stating the functions of certain components of blood
1. Red blood cells
The function of the red blood cells is to transport oxygen from the lungs to the body cells.
Red blood cells contain haemoglobin, an iron containing protein which binds reversibly with
oxygen.
Red blood cells are fully adapted to their function by the following characteristics:
 Biconcave disc shape gives it large surface area to carry more oxygen
 Haemoglobin to combine with oxygen
 No nucleus that takes up space.
2. White Blood Cells:
White blood cells are found in blood plasma. White blood cells are part of the Immune
System. Their role is to protect the body by killing bacteria which cause disease, also known
as pathogens. White blood cells are much bigger than red blood cells, have a nucleus, and are
present in fewer amounts. There are two types of white blood cells namely phagocytes and
lymphocytes.
Phagocytes are important in phagocytosis (the process of killing bacteria by engulfing them,
and digesting them using enzymes). Lymphocytes are important in antibody production
(Lymphocytes kill bacteria by secreting antibodies which kill the pathogens. Each pathogen
is killed by a specific type of antibody).
3. Platelets
Platelets prevent bleeding when the skin is cut, and stop bacteria from entering our systems
through the wound. Platelets work by causing clotting, when the skin is injured.
4. Blood plasma
Blood plasma makes up most of the blood. It is mostly water with some substances dissolved
in it. The blood plasma transports blood cells, ions, hormones, soluble nutrients, hormones
and carbon dioxide from one place to another.
Gas exchange and respiration
Gas exchange
Naming and identifying the lungs, diaphragm, ribs, intercostal muscles, larynx, trachea,
bronchi, bronchioles, alveoli and associated capillaries
Air inhaled moves from nostril to larynx to trachea to either of two bronchi to bronchioles
and then to alveoli (singular: alveolus). Bronchi form many smaller bronchioles. Bronchi,
bronchioles and alveoli are in the lung.
Page 21 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Alveoli and associated blood vessels
Listing the features of gas exchange surfaces
in animals:
These features include




Large surface area for faster diffusion
Thin surface to make diffusion
distance shorter and faster. Both the
alveoli and capillaries are one cell
thick.
Good blood supply and
Good ventilation with air
Stating the differences in composition between inspired and expired air limited to
oxygen, carbon dioxide and water vapour
Gas
Oxygen
Carbon dioxide
Water vapour
Inspired Air
21%
0.04%
Variable
Expired Air
16%
4%
High
Page 22 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Explaining the differences in composition between inspired and expired air
 Oxygen decreases in exhaled air because some of it is used by body cells in
respiration.
 Carbon dioxide increases because respiring cells produce carbon dioxide which is
then exhaled.
 Exhaled air contains more water vapour because gas exchange surfaces are made of
living cells which must be kept moist; some of this moisture evaporates into the air.
Using limewater as a test for carbon dioxide to investigate the differences in
composition between inspired and expired air
Exhaled air turns lime water more milky because of its high carbon dioxide content.
When you inhale, air moves into the
mouth from C to D via conical flask
A.
When you exhale, air moves from
the mouth from E to F via conical
flask B.
The higher carbon dioxide content in
exhaled air turns the lime water milky
white.
Investigating and describing the effects of physical activity on rate and depth of
breathing
Generally, the rate and depth of breathing increase with physical activity. An increased
carbon dioxide concentration in the blood causes an increased rate and depth of breathing.
Explaining the role of goblet cells, mucus and ciliated cells in protecting the gas
exchange system from pathogens and particles
Ciliated cells:
Ciliated cells are present in the trachea and bronchi of our respiratory system. Their function
is to use their cilia to move mucus up the trachea to the throat. The mucus traps bacteria and
dust particles. When it reaches the throat, the mucus is swallowed to the stomach where the
stomach acid kills the bacteria.
Goblet cells and mucus:
The mucus used to trap bacteria and dust particles is secreted by goblet cells which are next
to ciliated cells.
Page 23 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Tobacco smoking can cause chronic obstructive pulmonary
disease (COPD), lung cancer and coronary heart disease.
Describing the effects on the gas exchange system of
tobacco smoke and its major toxic components, limited
to carbon monoxide, nicotine and tar
Effects of Smoking tobacco:
• Cilia can’t vibrate anymore, the air inhaled isn’t clean.
Goblet cells release more mucus which makes the trachea
narrower.
• Nicotine increases heart beat rate and blood pressure.
• Carbon monoxide combines irreversibly with haemoglobin
(in place of oxygen); hence, less oxygen is transported to
cells.
Smoke particles get trapped inside the lungs. White blood cells try to remove them by
secreting chemicals which unfortunately end up doing serious damage to the lungs resulting
in chronic obstructive pulmonary disease (COPD).
Carbon monoxide combines with haemoglobin in red blood cells. This reduces the amount
of oxygen carried by blood to body cells because red blood cells end up carrying carbon
monoxide (which binds with haemoglobin much easily and strongly than oxygen).
Nicotine makes blood vessels get narrower. This can increase blood pressure, leading to
hypertension.
Tar contains carcinogens (cancer causing chemicals).
Respiration
The uses of energy in the body of humans:
Energy in the human body is used for muscle contraction, protein synthesis, growth and the
maintenance of a constant body temperature.
Defining aerobic respiration
Aerobic respiration refers to chemical reactions in cells that use oxygen to break down
nutrient molecules to release energy.
Stating the word and balanced chemical equation for aerobic respiration
Word equation for aerobic respiration is
Glucose + oxygen → carbon dioxide + water
Balanced chemical equation for aerobic respiration is
C6H12O6 + 6O2 → 6CO2 + 6H2O
Page 24 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Coordination and response
Hormones in humans
A hormone is a chemical substance, produced by a gland, and carried by the blood, which
alters the activity of one or more specific target organs.
Adrenaline is the hormone secreted in ‘fight or flight’ situations. Its effects are to increase
breathing and pulse rate, as well as to widen the pupils.
The role of the hormone adrenaline in the chemical control of metabolic activity,
including increasing the blood glucose concentration and pulse rate.
Adrenaline increases your metabolic rate so that you have enough energy for fighting or
running away etc. When adrenaline reaches the heart it causes the cardiac muscle to contract
and relax rapidly so that oxygen and glucose reach the muscles of the body faster. Adrenaline
also makes the liver convert glycogen into glucose and secrete it into the blood to be used in
respiration. When adrenaline reaches the diaphragm and the intercostal muscles of the ribs, it
makes them contract and relax faster too to increase rate of breathing. These changes cause
an increase in the respiration rate so that lots of energy is being released.
Giving examples of situations in which adrenaline secretion increases
Adrenaline is released in Fight and flight situations.
Tropic responses
Tropisms are directional growth responses to environmental stimuli.
Gravitropism is a response in which parts of a plant grow towards or away from gravity.
Phototropism is a response in which parts of a plant grow towards or away from the
direction from which light is coming.
Since auxin is a chemical ,phototropism and gravitroprism of a shoot are examples of the
chemical control of plant growth.
Investigating gravitropism and phototropism in shoots and roots
Root
Shoot
A seed is pinned in the dark as shown. The
shoot will bend upwards whilst the root bends
downwards due to gravitropism. The shoot
displays negative gravitropism whilst the root
displays positive gravitropism.
Explaining the role of auxin in controlling
shoot growth
[check notes that follow]
Page 25 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Auxin is made only in the tip of a shoot from where it spreads through to the plant. Auxin
stimulates cell elongation/ growth. Auxin is only produced by the growing tip of the plant. If
this is removed, growth ceases.
Diagram A (phototropism): When light shines onto a shoot from all around, the shoot
grows straight upwards because auxin is evenly distributed around the tip of the shoot
causing equal growth on all sides. However, when light shines onto a shoot from one side, the
shoot grows towards the light because auxin at the tip concentrates on the shady side thus
causing rapid growth on the shady side than the bright side. This is positive phototropism.
Diagram B (gravitropism): If a potted plant is placed on its side in a dark room overnight,
the shoot will bend upwards. Since there is no light, the result should be a response to gravity.
Auxin collects on the lower side of the stem, causing faster growth there. Therefore, the stem
curves upward. The shoot is displaying negative gravitropism.
Diagram C (gravitropism): the
root and shoot are displaying
gravitropism.
Tropism can be positive or
negative. Positive tropism means
growing towards. Negative tropism
means growing away from. The
root is displaying positive
gravitropism.
Page 26 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Reproduction
Asexual and sexual reproduction
Asexual reproduction:
Asexual means not sexual. This means that this kind of reproduction does not involve sex.
Asexual reproduction is the production of genetically identical offspring from one parent. It
is simply a single organism growing a new organism from itself e.g. in bacteria, fungi and
potato plants.
Bacteria reproduce by a process called binary fission. In
binary fission, one bacterium grows an exact copy of its
DNA coil which carries its genetic information. Then the
bacterium completely divides with one DNA coil in the
parent and one in the daughter bacterium. Each
bacterium can undergo binary fission once every 20
minutes making them able to reproduce massive
numbers from one parent in very little time.
The sporangium of Fungi produce productive structures
called spores that can grow into other fungi. At some
point, the sporangium will burst open dispersing the
spores into the air. If a spore falls on an area of
favourable conditions it will germinate and grow into a
new identical fungus.
A potato plant starts as a lateral bud which
grows from a potato tuber under the soil. The
bud then forms a plant which will form more
potato tubers. These tubers can also form
lateral buds which grow into potato plants.
Page 27 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Sexual reproduction:
Sexual reproduction is a process involving the fusion of the nuclei of two gametes (sex cells)
to form a zygote and the production of offspring that are genetically different from each
other.
Sexual reproduction in plants
Identifying and drawing the sepals, petals, stamens, filaments and anthers, carpels,
style, stigma, ovary and ovules, of an insect-pollinated flower
Identifying and describing the anthers and
stigmas of a wind pollinated flower
Methods of Pollination:
Pollination is the transfer of pollen grains from the male part of a flower (anther) to the
female part of a flower (stigma). There are two methods of pollination, insect pollination and
wind pollination. Some flowers pollinate by insects while others pollinate by wind.
Functions of certain parts of a flower
Sepals – Protect the flower when it is in bud stage.
Petals –They are brightly coloured in insect-pollinated plants to attract insects, and
form a platform for insects to land on.
Anther – Contains pollen grains. Pollen grains in insect-pollinated plants are heavy
and sticky.
Stigma – Receptor of pollen grains. Secretes a fluid that stimulates germination of
pollen grains.
Ovary – Each ovary contains one or more ovules.
Ovule – Contains female gametes.
Page 28 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Distinguishing between the pollen grains of insect pollinated and wind-pollinated
flowers
Pollination is the transfer of pollen grains from the anther to the stigma
Part of flower
Pollen grains
Insect pollinated
Fairly abundant, large and
sticky. Sticky so that they
easily attach to insects.
Wind pollinated
Very abundant, small and
light so that wind easily
carries them.
Agents of pollination are wind and insects. Fertilisation occurs when a pollen nucleus fuses
with a nucleus in an ovule.
Describing the structural adaptations of insect and wind pollinated flowers
Insect pollinated
Brightly coloured and large petals to attract insects
Strong attractive scents to attract insects
Sticky or spiky pollen grains to attach pollen to
bodies of insects
Contain nectarines (at the base of petals) to attract
insects
Stigma inside flower such that insects brush past it
to reach nectar
Anthers inside flower such that insects brush past it
to reach nectar
Produce fairly large quantities of pollen because
some will be eaten or delivered to the wrong flower
Wind pollinated
Small dull petals/ no petals at all
No scent
Smooth and light so that it travels easily in air
No nectaries
Large stigmas which hang outside the flower to
capture pollen grains carried by the wind
Anthers hang outside the flower to easily distribute
pollen grains in air
Produce very large quantities of pollen because
some of it is blown away and lost
Investigating and stating the environmental conditions that affect germination of seeds:
limited to the requirement for water, oxygen and a suitable temperature
A seed remains dormant until it is put in suitable conditions to start growing.
These are:
• Water
• Air (oxygen)
• Suitable temperature
Conditions in each test tube





Tube A: water; air; suitable temperature
Tube B: water; air
Tube C: water; air; suitable temperature
Tube D: water; suitable temperature
Tube E: air; suitable temperature
Results: germination occurs only in test tubes A and C
Page 29 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Pyrogallol absorbs oxygen.
Sexual reproduction in humans
Identifying and naming, on diagrams, parts of the male reproductive system: the testes,
scrotum, sperm ducts (vas deferens), prostate gland, urethra and penis
[Note that vas deferens are also known as sperm ducts]
Page 30 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Function of the parts of the male reproductive system
Testes: a male human has two testes. A testis (singular) produces male gametes
(sperms)
Scrotum: The scrotum is a sac which holds the testes outside the body
Sperm Ducts (Vas deferens): Sperm ducts transfer the sperms from the testis to
the urethra
Prostate Gland: The prostate gland secretes a fluid for the sperms to swim in,
forming a mixture called semen.
Urethra: The urethra carries semen and urine out of the body.
Penis: The penis transfers semen into the vagina during sexual intercourse.
Identifying and naming, on diagrams, parts of the female reproductive system: the
ovaries, oviducts, uterus, cervix and vagina
Stating the functions of the parts of the female reproductive system
Oviducts (fallopian tube): oviducts transfer eggs to the uterus. Fertilisation
takes place along the oviducts.
Ovaries : ovaries release female gametes (eggs)
Uterus: the fetus develops in the uterus
Cervix: the cervix is a ring of muscle at the opening of the uterus
Vagina: the vagina receives the penis during sexual intercourse
Fertilisation
Fertilisation is the fusion of the nuclei from a male gamete (sperm) and a female gamete
(egg cell/ovum).
Comparing Male and Female Gametes:
Size: egg cells are much larger than sperms. This is because they need space to store nutrients
to feed the embryo before it reaches the uterus.
Structure: sperms have a head, a middle piece and long tails which help them swim their
way to the egg. The middle part of sperms contains a large number of mitochondria to release
Page 31 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
a lot of energy which they use to swim towards egg cells. Egg cells have a spherical structure
and are made up of a nucleus, cytoplasm, cell membrane and a layer of jelly.
Motility: motile means capable of moving spontaneously as a whole. Sperms are motile
whilst egg cells are not. Eggs are unable to move by themselves, they are swept to the uterus
by cilia on the walls of the oviduct. Sperms have tails that allow them to swim.
Numbers: a woman releases one egg at a time. Sperms, however, are in larger quantities to
increase the chance of successful fertilization.
The adaptive features of sperm, limited to flagellum and the presence of enzymes
The tail (flagellum) beats to propel the sperm towards the egg.
The head contains digestive enzymes which break down the outer membrane of the ovum,
allowing for fertilization to take place.
The middle piece contains numerous mitochondria to provide adequate energy for the sperms
to swim to the egg [note that this point is not required by the syllabus].
The adaptive features of egg cells, limited to energy stores and a jelly coating that
changes after fertilization
The egg contains nutrients or energy stores.
They also contain a jelly coating that changes after fertilization.
The menstrual cycle
 The menstrual cycle can be described as “changes in the ovaries and in the lining of
the uterus” (knowledge of sex hormones is not required)
Changes in the ovaries: A follicle containing an ovum develops in the ovary, as the uterus
lining builds up. The follicle then bursts (around day 14), releasing an egg cell from the
ovary. The release of the ovum is called ovulation. The follicle turns into a corpus luteum.
Changes in the uterus: A woman usually releases one egg every month. The lining of the
uterus becomes thick and spongy in preparation for a fertilised egg cell. The thickening of
the uterus lining begins before an egg cell is even released, and just after menstruation, from
the previous menstrual cycle, ends. If the egg cell is not fertilised, it dies before it reaches the
uterus. The unfertilised egg does not sink into the spongy uterus lining, but continues
onwards, down through the vagina. The spongy uterus lining then gradually disintegrates
and is slowly lost through the vagina. This is called menstruation, or a period. It usually lasts
for about five days. After menstruation, the lining of the uterus builds up again, so that it
will be ready to receive the next egg, if it is fertilised. Menstruation and the menstrual cycle
are two different things. The menstrual cycle, on the other hand, can take about 28 days (the
menstrual cycle differs amongst women, some take more and others take less days). A mature
ovum (egg cell) is released on day 14 and if not fertilized it can die after 1 or 2 days.
Page 32 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Fertilization results in the
formation of a zygote
which further forms an
embryo in early
development.
An embryo is a ball of
cells that implants into the
wall of the uterus.
The functions of the umbilical cord, placenta, amniotic sac and amniotic fluid
1. Umbilical cord:
The umbilical cord connects the embryo to the placenta. This allows for the exchange
of oxygen and dissolved nutrients from the mother’s blood to the child’s blood. It also
offers a pathway by which waste products leave the child.
2. Placenta:
 Provides nutrients and oxygen for the embryo.
 Removes waste materials such as urea and carbon dioxide.
 Allows protective antibodies to diffuse from maternal blood into embryonic blood.
 Provides a barrier preventing maternal blood and embryonic blood from mixing.
3. Amniotic sac:
contains amniotic fluid.
4. Amniotic fluid:
 Absorbs shock, supports and protects the embryo from physical injury
 Lubricates the vagina during birth to reduce friction
 Allows the fetus to move freely during development
The functions of the placenta and umbilical cord are
Oxygen and nutrients in the mother’s blood diffuse across the placenta into the fetus’s blood,
and are then carried along the umbilical cord to the fetus. Carbon dioxide and waste materials
diffuse from the fetus’s blood to the mother’s blood, and are carried away in the mother’s
blood. The placenta provides a barrier to toxins by preventing maternal blood and embryonic
blood from mixing.
Page 33 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
HIV and AIDS
AIDS is a disease caused by the HIV (human immunodeficiency virus). Human
immunodeficiency virus (HIV) infection may lead to acquired immune deficiency syndrome
(AIDS). The virus can live for years in the body before it starts showing symptoms. AIDS is
Acquired Immune Deficiency Syndrome. The disease prevents white blood cells from killing
bacteria and viruses, so one or more weak viral or bacterial infections take advantage of the
person’s weak immune system to kill the patient. There is no cure for AIDS.
HIV is transmitted:
 By sexual intercourse with an infected person
 By sharing and reusing contaminated needles during intravenous drug use, getting a
tattoo and body piercing
 By receiving a blood transfusion from an infected donor
 During pregnancy and childbirth. An infected mother can pass on the virus to her
child
Spread of HIV can be prevented by:
 Having protected sexual intercourse. A condom reduces the risk of infection.
 Abstinence from sex or having sex with only one faithful partner
 Not sharing objects that could be contaminated with blood or bodily fluids such as
hypodermic syringes and razors
 Proper screening of blood in a blood bank for HIV infection to reduce chances of
transmission during blood transfusions
 Infected mothers should undergo antiretroviral therapies and give birth by caesarean
section to minimise risk of transmission to the fetus. Breastfeeding should be avoided
after birth.
 Visiting reliable and hygienic operators for tattoos, piercings or acupuncture where
needles are sterilized
Organisms and their environment
All energy in biological (living systems) is ultimately derived from sunlight.
Definition of key terms

A food chain shows the transfer of energy from one organism to the next, beginning
with a producer.

A food web is a network of interconnected food chains.
Page 34 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section

A producer is an organism that usually uses energy from sunlight to make its own
organic nutrients through photosynthesis.

A consumer is an organism that gets its energy by feeding on other organisms.

A herbivore is an animal that gets its energy by eating plants.

A carnivore is an animal that gets its energy by eating other animals.

A decomposer is an organism that gets its energy from dead or waste organic matter.

An ecosystem is a unit containing all ofthe organisms and their environment,
interacting together, in a given area, e.g. a lake

A trophic level is the position of an organismin a food chain or food web.
The transfer of energy between trophic levels
A pyramid of energy represents the total energy in the various trophic levels of a food chain.
 Producers occupy the first trophic level at the base of the pyramid. This trophic level
has the largest amount of energy.
 The quantity of energy which is available to the next trophic level decreases from one
trophic level to another.
Explaining why food chains usually have fewer than five trophic levels
Since the quantity of energy decreases from one trophic level to another, the number of
sustainable trophic levels is limited to five because there isn’t enough energy to support a
sixth trophic level. Some energy is lost during transfer between organisms. Part of the food
input is wasted as faeces and in respiration. These losses are repeated at every transfer.
Constructing simple food chains
Tree → caterpillar → small bird → hawk
Grass → Grasshopper → Frog → Snake
A food web
Identifying producers and
consumers as trophic levels
It is important to understand
that producers, primary
consumers, secondary
consumers, tertiary consumers
and quaternary consumers are
individually referred to as
trophic levels in food webs and
food chains.
Tree → caterpillar → small bird
→ hawk
The caterpillar is trophic level 2
Page 35 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
Classification of consumers by virtue of their position in a food chain.
Consumers obtain their energy by consuming other organisms. They occupy a few trophic
levels:
 Primary consumers feed on primary producers directly. They are called herbivores.
 Secondary consumers are carnivores that eat herbivores.
 Tertiary consumers are carnivores that eat other carnivores.
Human influences on ecosystems
Describing the carbon cycle, limited to photosynthesis, respiration, feeding,
decomposition, fossilisation and combustion
The carbon cycle is a natural global cycle of the element carbon. It is what maintains a
constant level of carbon dioxide in air (0.03%). The cycle goes as follows:
• Plants absorb carbon dioxide from air use it for a process called photosynthesis to produce
glucose and oxygen
6CO2 + 6H2O → C6H12O6 + 6O2
•The carbon is now stored in plants as glucose. One of two things happen, either the plant
gets eaten by animals or humans in a process called feeding, or the plant dies and is decayed
by decomposers in a process called decomposition.
• If the plant is eaten by animals or humans, glucose in the plant is used by them in a process
called respiration to release energy for their body. In addition, fossil fuels and wood can be
burnt to release carbon dioxide and energy in a process called combustion. Both combustion
and respiration have the same chemical equation as shown below. You do not need to
remember this chemical equation.
C6H12O6 + 6O2 → 6CO2 + 6H2O
Page 36 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Biology section
• Respiration is the opposite of photosynthesis.
• If plants and animals die, and their remains are buried underground and exposed to certain
conditions, fossil fuels are formed by a process called fossilisation. Fossil fuels contain
carbon.
• Power stations burn carbon-containing fuels like coal (a fossil fuel). This is a combustion
reaction. Carbon dioxide produced is released to the air through chimneys of power stations.
Discussing the effects of the combustion of fossil fuels and the cutting down of forests on
the oxygen and carbon dioxide concentrations in the atmosphere
Combustion of fossil fuels
Combustion of fossil fuels (coal, oil and natural gas) uses up oxygen and gives out carbon
dioxide; hence, it leads to the decrease in oxygen concentrations and the increase in carbon
dioxide concentrations in the atmosphere.
Cutting down of forests
Since green plants absorb carbon dioxide during photosynthesis to form carbohydrates,
cutting down trees reduces the number of green plants available for photosynthesis, thus
leading to a buildup of carbon dioxide concentration in air.
The undesirable effects of deforestation
The undesirable effects of deforestation include habitat destruction, extinction of some flora
and fauna that depend on that flora, soil erosion, siltation, flooding and an increase of carbon
dioxide in the atmosphere.
Eutrophication
Eutrophication is summarized by the following points
Excess nitrates (and other ions) from fertilizers run off into water bodies leading to an
increased growth of producers in water bodies e.g. algae. When these producers die, it leads
to increased decomposition of producers, followed by increased aerobic respiration by
decomposers. A reduction in dissolved oxygen then occurs, leading to the death of aquatic
organisms that require dissolved oxygen in water.
Page 37 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
The particulate nature of matter
1. Stating the distinguishing properties of solids, liquids and gases
2. Describing the structure of solids, liquids and gases in terms of particle
separation, arrangement and types of motion
Describing the changes of state in terms of melting, boiling, evaporation, freezing and
condensation
Explaining changes of state in terms of particle theory and the energy changes involved
1. Melting: Occurs at the melting point. Particles absorb heat and vibrate more vigorously,
allowing them to overcome the attractive forces holding them in fixed positions.
Page 38 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
2. Freezing: Occurs at the melting point. Particles release heat and move more slowly.
Attractive forces are formed and the particles are forced to be held in a fixed and orderly
arrangement.
3. Boiling: Occurs at the boiling point. Particles absorb heat and gain more kinetic energy.
The particles move fast enough to completely overcome the forces of attraction acting
between them.
4. Evaporation: Occurs below the boiling point. Particles at the surface gain sufficient energy
to escape into the surroundings.
5. Condensation: Occurs at the boiling point. Particles release heat and move more slowly.
The forces of attraction are then able to hold the particles closely.
Describing qualitatively the pressure and temperature of a gas in terms of the motion of
its particles
A high pressure results in a small volume thus limiting the motion of gas particles.
A high temperature results in high kinetic energy of gas particles thus increasing the motion
of gas particles.
Demonstrating understanding of the terms atom, molecule and ion

All matter is made up of tiny particles

These particles can be atoms, molecules or ions
An atom is the smallest part of an element that can take part in a chemical reaction. An atom
has sub atomic particles namely electrons (which are found in electron shells situated around
the nucleus), protons and neutrons (both of which are found in the atom‟s nucleus).
Page 39 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
A molecule is a group of two or more atoms chemically joined together, e.g. a chlorine
molecule has 2 chlorine atoms chemically combined together. A water molecule has 2
hydrogen atoms and one oxygen atom chemically combined together.
An ion is a positively or negatively charged species. An atom has an equal number of
positively charged protons and negatively charged electrons. This makes an atom to be
neutral. Ions arise when atoms lose or gain electrons. When atoms lose electrons, positively
charged ions are formed because the total positive charge of the protons would not be
cancelled by the total negative charge of the electrons. Similarly, when an atom gains extra
electrons, it will not have extra protons to cancel out the negative charge of the added
electrons, resulting in a negatively charged ion. A negatively charged ion is called an anion.
A positively charged ion is a called a cation.
Experimental techniques
Measurement
Naming and suggesting appropriate apparatus for the measurement of time,
temperature, mass and volume, including burettes, pipettes and measuring cylinders
Apparatus
Used to measure
Stop watch
Time
Thermometer
Temperature
Electronic balance
Mass
Measuring cylinder, burette and pipette
Volume
Criteria of purity
Interpreting simple chromatograms
Chromatography is a process used to separate and identify two or more substances from a
mixture. It is also used to find the number of components in a substance, hence, determining
the purity of the substance. A pure substance has one substance in it; an impure substance has
two or more. In addition, a pure substance has a definite, sharp, melting point and boiling
point.
Page 40 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Interpreting simple chromatograms, including the use of R f values
Rf values have
no units
Substance 1 contains A, B and C. Substance 2 contains B. Substance 3 contains D. Substance
4 contains C.
Rf value for each component =
=
distance moved by substance
distance moved by solvent
distance from starting point to solvent front
distance from starting point to position of each component
Rf values for the above 3 situations are
48mm/80mm = 0.6
72mm/120mm = 0.6
120mm/200mm = 0.6
and
Page 41 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Methods of purification
1. Describing and explaining methods of separation and purification by the use of a
suitable solvent, filtration, crystallisation, distillation, fractional distillation and
paper chromatography
2. Suggesting suitable separation and purification techniques, given information
about the substances involved
1. Filtration
Filtration is used to separate a mixture of a liquid (or solution) and an insoluble solid. The
insoluble solid is collected as the residue (on the filter paper) while the liquid is collected as
the filtrate.
2. Evaporation
This method is used to evaporate off the solvent from a solution to obtain the dissolved
substance. This is only applicable to substances that do not decompose upon heating.
3. Crystallisation
Crystallisation can be used to recover a dissolved substance from its solution. This is carried
out by heating a solution until it is saturated. The saturated solution is then left to cool,
allowing for the substance to crystallise.
Page 42 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
4. Distillation
Distillation is used to separate a liquid from a mixture. The substances in the mixture must
have large differences in boiling points for the pure liquid to be obtained.
5. Fractional Distillation
In cases where a mixture contains liquids that have relatively close boiling points, fractional
distillation is used for purification. The fractionating column aids in separating the vapour
into individual components, which allow for the collection of pure substances.
6. Separation using a Separating Funnel
The separating funnel is used to separate a mixture of liquids that have different densities.
The liquid with lower density is found in the top layer while the liquid with higher density is
found in the bottom layer.
7. Paper Chromatography
This is used in the separation of small quantities of mixtures. The mixture is separated based
on i) differences in solubility of its components in a particular solvent and ii) differences in
the way the components are attracted to the chromatography paper. The identity of a
component in the mixture can be deduced by comparing the Rf value obtained in the
chromatogram with existing Rf values of known substances.
Page 43 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Atoms, elements and compounds
Physical and chemical changes
Identifying physical and chemical changes, and understanding the differences between
them
A physical change is a change in which no new chemical substance forms; melting and
boiling are physical changes.
A chemical change is a change in which a new chemical substance forms. Electrolysis is an
example of a chemical change.
Elements, compounds and mixtures
Describing the differences between elements, mixtures and compounds, and between
metals and non-metals
An element is a substance that cannot be broken down into simpler substances by chemical
or physical means. An element is made up of many identical atoms. Atoms of different
elements differ. Their differences are caused by the differences in the numbers of sub atomic
particles which they contain. The element sodium contains many sodium atoms in it. The
element calcium contains many calcium atoms in it. Elements can be combined physically to
form mixtures, or chemically to form compounds. Similarly, compounds can also be
combined physically and chemically to form mixtures and other compounds respectively.
Compound
Mixture
1. Component substances cannot be
separated by physical means.
Chemical methods are required to
separate component substances.
Component substances can be separated
by physical means
2. Its physical and chemical properties
are different from those of its
constituent substances
Its physical and chemical properties are
the same as those of its constituent
substances
3. Composition by mass is fixed
Composition by mass varies
4. Has fixed melting and boiling points Has variable melting and boiling points
Page 44 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Property
Metals
Non-metals
Appearance
Lustrous (shiny)
Dull
State at room temperature
Solid (except mercury
which is a liquid)
About half are solids and
the other half are gases.
Only one (Bromine) is a
liquid
Malleable or brittle
Malleable (easily shaped by
hammering) because they
bend without breaking
since their atoms can easily
slide over each other
Brittle (break when
hammered)
Conduction (thermal and
electrical)
Good because they possess
either free or mobile ions or
electrons to carry current
or heat.
Generally poor (most are
insulators) because they do
not possess free or mobile
ions or electrons to carry
current or heat.
Melting and boiling points
High melting and boiling
points
Generally low melting and
boiling points.
Density
High density
Low density
Magnetism
Only nickel, iron and cobalt None are magnetic
are magnetic
Sound produced when
struck
Sonorous (make a bell or
reverberative sound when
struck)
Make a dull sound
Ductile
Ductile (Easily drawn into
wire)
Not ductile
Defining the terms solvent, solute, solution and concentration
Solute the substance you dissolve in the solvent, to make a solution
Solvent the liquid in which a solute is dissolved, to make a solution
Solution a mixture obtained when a solute is dissolved in a solvent
Concentration tells you how much of one substance is dissolved in another; usually given as
gdm-3 or moldm-3. Concentration is also defined as the amount of solute dissolve in a given
volume of solvent.
Page 45 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Atomic structure and the Periodic Table
Describing the structure of an atom in terms of a central nucleus, containing protons
and neutrons, and ‘shells’ of electrons
The nucleus is located in the centre of the atom and contains
protons and neutrons. In the case of sulfur, the nucleus has 16
protons and 16 neutrons. Electrons are arranged in shells around
the nucleus of an atom. The first shell can contain up to 2
electrons and the second and third shells hold a maximum of 8
electrons. Sulfur is represented by the symbol
, indicating
that it has 16 protons and 16 neutrons. The number of neutrons is
calculated by subtracting the atomic number from the nucleon
number. Since it is electrically neutral, it has 16 electrons as well.
The first electron shell contains 2 electrons, the second shell
contains 8 electrons and the third shell contains 6 electrons. The
electronic configuration can be written as 2.8.6.
1. Describing the build-up of electrons in ‘shells’ and understanding the
significance of the noble gas electronic structures and of the outer shell electrons
(The ideas of the distribution of electrons in s and p orbitals and in d block
elements are not required)
2. Describing the formation of ions by electron loss or gain
In terms of the buildup of electrons in shells, electrons occupy the shell closest to the nucleus
before filling up other shells further from the nucleus. In drawing the structure of an atom,
only shells containing electrons are shown. The first shell should not contain more than 2
electrons. The remaining shells normally contain a maximum of 8 electrons.
Atoms usually want to have a configuration which is such that they have full shells only. This
configuration is referred to as the noble gas electronic structure. Atoms achieve this noble gas
electronic structure by either losing or gaining the number of electrons preventing them from
achieving this electronic arrangement. These electrons are lost or gained by the outermost
electron shell only. Usually, atoms with electronic configurations whereby the outer shell has
3 or less electrons tend to lose these electrons to achieve a noble gas electronic structure.
Those with 4 outermost electrons can either lose or gain these to form noble gas electronic
structures, whilst those with more than 4 find it easier to gain the electrons required to reach
an octet (from eight) state or noble gas electronic structure. When atoms lose or gain
electrons, ions are formed. These ions tend to be more chemically stable than the atoms.
Page 46 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Stating the charges and approximate relative masses of protons, neutrons and electrons
Defining and using proton number (atomic number) as the number of protons in the
nucleus of an atom
Proton number is the number of protons in the atom of an element; it is sometimes called
the atomic number .
Protons and neutrons are found in the nucleus of an atom. They are collectively known as
nucleons.
Electrons are found outside the nucleus. They are arranged in shells, also referred to as
energy levels, which surround the nucleus.
Defining and using nucleon number (mass number) as the total number of protons and
neutrons in the nucleus of an atom
Nucleon number is the number of protons plus neutrons in an atom of an element; it is
sometimes called the mass number.
Using proton number and the simple structure of atoms to explain the basis of the
Periodic Table, with special reference to the elements of proton numbers 1 to 20
Atoms in the periodic table are arranged according to proton number from lowest to highest.
The ascension goes from left to right and from one horizontal period to another e.g period 3 is
sodium (proton number 11; electronic configuration 2,8,1) to argon (proton number 18;
electronic configuration 2,8,8).
Note: a copy of the Periodic Table, as shown in the Appendix, will be provided in
Papers 1, 2, 3 and 4.
Ions and ionic bonds
Formation of Ions
An atom is most stable when the valence electron shell is completely filled. Atoms of
elements either gain or lose electrons to attain a stable electronic configuration.
Non-metals usually gain electrons to form negative ions (anions) while metals usually lose
electrons to form positive ions (cations).
Page 47 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
The charge of an ion can be found by finding the difference between the number of electrons
and the number of protons.
Using dot-and-cross diagrams to describe the formation of ionic bonds between Group I
and Group VII
This type of bonding takes place between oppositely-charged ions. This usually occurs for
compounds made from a metal and a non-metal. Ionic bonds are formed by electron transfer,
where metal atoms donate electrons to non-metal atoms. The transfer of electrons forms
anions and cations. These ions are arranged in an ionic lattice and are held together by strong
electrostatic forces of attraction. An example of dot-and-cross diagrams that illustrates the
formation of an ionic bond are shown below
Sodium (metal) reacts with chlorine (non-metal) to form sodium chloride, NaCl
Describing the formation of ionic bonds between metallic and non-metallic elements to
include the strong attraction between ions because of their opposite electrical charges
Ionic bonding should be defined as guided by the following steps
1. Metal atoms lose electrons to form cations
2. The electrons lost by metal atoms are gained by non-metallic atoms to form anions
3. The oppositely charged ions are held together by strong electrostatic forces of
attraction acting between these ions because of their opposite electrical charges.
4. The attractions described in (3) are ionic bonds.
It should be noted that an ionic bond can only occur between metals and non-metals only!!!
Describing the lattice structure of ionic compounds as a regular arrangement of
alternating positive and negative ions, exemplified by the sodium chloride structure
The lattice structure of ionic compounds is a regular arrangement of alternating positive and
negative ions, eg. the sodium chloride structure
Page 48 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Structure

Ionic substances appear as giant lattice
structures with a regular arrangement of
alternating positive and negative ions.
Molecules and covalent bonds
Stating that non-metallic elements form simple molecules with covalent bonds between
atoms
When non metallic elements react with each other, simple molecules are formed. The atoms,
of the different elements making up each simple molecule, are joined together by covalent
bonds. Weak intermolecular forces (not covalent bonds) hold different molecules together.
Describing the formation of single covalent bonds in H2, Cl2, H2O, CH4, NH3 and HCl as
the sharing of pairs of electrons leading to the noble gas configuration including the use
of dot-and-cross diagrams

Covalent bonding is the sharing of a pair of electrons to gain an electronic
configuration or structure like that of an inert or noble gas.

Covalent bonds occur between non-metals only.

In covalent bonds, an atom usually shares the same number of electrons as it needs to
form the 2 or 8 valence electrons. E.g. oxygen is 2,6 and carbon is 2,4. Oxygen needs
2 so it shares two electrons forming 2 covalent bonds. Carbon needs 4 and shares 4
forming 4 covalent bonds. One carbon would need to bond with 2 oxygen atoms
giving O=C=O

The shared electrons appear in pairs
Page 49 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
From left to right, top row to bottom, we have simple molecules of
HCl; H2O; Cl2; CO2; CH4; NH3
Using and drawing dot-and-cross diagrams to represent the bonding in the more
complex covalent molecules such as N2, C2H4, CH3OH, and CO2
Page 50 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Describing the differences in volatility, solubility and electrical conductivity between
ionic and covalent compounds
Property
Ionic compounds
Covalent compounds
Volatility
Not volatile because of
strong ionic bonds holding
the particles (ions) together
Volatile because of weak
intermolecular forces
holding the particles
(molecules) together
Solubility
Soluble in water
Not soluble in water
Electrical conductivity
Conduct electricity only in
molten or aqueous state
Do not conduct electricity
(or are poor conductors)
Explaining the differences in melting point and boiling point of ionic and covalent
compounds in terms of attractive forces
Ionic compounds have higher melting and boiling points because ionic bonds have stronger
attractive forces holding the particles (ions) together as compared to the weak intermolecular
forces holding the particles (molecules) together in covalent bonding.
Stoichiometry
Using the symbols of the elements and writing the formulae of simple compounds
Element
Symbol
Hydrogen
H
Helium
He
Lithium
Li
Beryllium
Be
Boron
B
Carbon
C
Nitrogen
N
Elements have symbols. These are usually
either one or two letters, and are not
necessarily letters extracted from the name of
the element e.g. lead is Pb. The first letter is
usually a capital letter and the second letter is
a small letter.
Determining the formula of an ionic compound from the charges on the ions present

Determine the formula of an ionic compound made by the ions Al3+ and SO42-
Page 51 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Ions present:
Al3+
SO42-
Al2
(SO4)3
Therefore, the formula is Al2(SO4)3


Determine the formula of the ionic compound made by the ions Fe 3+ and O2Answer should be Fe2O3
If the charges on the ions are the same eg. An+ and Bn- ions we get AB. Mg2+ & O2give MgO. Similarly Na+ & Cl- give NaCl.
Deducing the formula of a simple compound from the relative numbers of atoms
present
Water has two hydrogen atoms and one oxygen atom; hence, its formula is H2O
Deducing the formula of a simple compound from a model or a diagrammatic
representation
[To be done practically]
Constructing and using word equations
1. calcium burns in oxygen to form calcium oxide
The word equation is
calcium + oxygen → calcium oxide
2. chlorine reacts with potassium bromide to form bromine and potassium chloride
The word equation is
chlorine + potassium bromide → bromine + potassium chloride
Interpreting and balancing simple symbol equations
The number of atoms of each element on the left side of the equation should be equal to the
number of atoms of that element on the right side of the equation, regardless of the fact that
the reactants and products differ.
The formulae of the reactants or products should not be changed during balancing; meaning
only the numbers in front of the chemical substance can be changed.
Balance the following equations:
1.
2.
3.
4.
5.
CaCO3 + HNO3 → Ca(NO3)2 + H2O + CO2
Ca+H2O→Ca(OH)2+H2
Pb(NO3)2+NaI→PbI2+NaNO3
Al2(SO4)3+NaOH→Al(OH)3+Na2SO4
Al(OH)3+NaOH→NaAlO2+H2O
Answers on next page
Page 52 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
1.
2.
3.
4.
5.
CaCO3 + 2HNO3 → Ca(NO3)2 + H2O + CO2
Ca+ 2H2O→Ca(OH)2+H2
Pb(NO3)2+ 2NaI→PbI2+ 2NaNO3
Al2(SO4)3+ 6NaOH→ 2Al(OH)3+ 3Na2SO4
Al(OH)3+NaOH→NaAlO2+ 2H2O
Electricity and chemistry
Defining electrolysis as the breakdown of an ionic compound when molten or in aqueous
solution by the passage of electricity
Electrolysis the process of
breaking down an ionic
compound, when molten or in
aqueous solution, by passing
electricity through it. The heat in
the diagram below is for melting
the compound. Aqueous
solutions will not have the heat
supply as shown below.
Using the terms inert electrode, electrolyte, anode and cathode
An inert electrode is an electrode which is not changed during electrolysis; all it does is
conduct the current.
An electrolyte is the liquid through which the current is passed, in electrolysis; the current is
carried by ions in the electrolyte.
An anode is the positive electrode of an electrolytic cell.
A cathode is the negative electrode of an electrolytic cell.
Describing electrolysis in terms of the ions present and the reactions at the electrodes, in
terms of gain of electrons by cations and loss of electrons by anions to form atoms
1. Describing the electrode products and the observations made, using inert
electrodes (platinum or carbon), in the electrolysis of:
 molten lead(II) bromide
 concentrated aqueous sodium chloride
 dilute sulfuric acid
Page 53 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Example
Electrolysis of molten PbBr2
Ions present: Pb2+ and Br- only.
Reaction at the Anode
Br- loses electrons at the anode to form Br atoms. The Br atoms, which are created, bond
together to make Br2 gas. This is because elements in group 7 exist as X2 molecules.
2Br-(aq) → Br2(g)+ 2eReaction at the Cathode
Pb2+ gains electrons at the cathode to form Pb atoms.
Pb2+(aq) + 2e- → Pb(s)
Electrolysis of Aqueous Solution

Aqueous solutions contain additional H+ and OH- ions from water, totalling 4 ions in
the solution: 2 from electrolyte and 2 from water. Only 2 of these ions are selectively
discharged.
Examples
Electrolysis of Concentrated NaCl
Ions Present: Na+, H+, OH- and ClReaction at the Anode



Cl- ions lose electrons at the anode to form Cl atoms.
The Cl atoms formed combine together to make Cl2 molecules.
2Cl- (aq) → Cl2(g) + 2e-
Reaction at the Cathode


H+ ions gain electrons at the cathode to form H atoms which then combine to make
H2(g) (hydrogen gas). Like group 7 elements, hydrogen also exists as X2 molecules.
2H+ (aq) + 2e- → H2(g)
Electrolysis of dilute H2SO4 (referred to as the electrolysis of water)
Ions Present: H+, OH- and SO42-
(note that the source of H+ is both acid and water)
Reaction at the anode
Page 54 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section

OH- ions lose electrons at the anode to become O2 and H2O.
4OH-(aq) → O2 (g) + 2H2O (l) + 4e-
(remember this equation)
Reaction at the cathode


H+ ions gain electrons at the cathode to form H atoms which then combine to form
hydrogen gas (H2).
2H+(aq) + 2e- → H2 (g)
Predicting the products of the electrolysis of a specified molten binary compound
Generally, a molten binary compound only has a single cation and a single anion. The cation
is discharged at the negative electrode (cathode). The negative ion is discharged at the
positive electrode (anode). Negative ions are discharged by removing electrons from them
and positive ions are discharged by adding electrons to them. The number of electrons added
or removed is such that no charge remains at the end of the discharging process.
Energy changes in chemical reactions
Describe the meaning of exothermic and endothermic reactions
Chemical reactions that release energy to the surroundings are described as exothermic
reactions. In an exothermic reaction the temperature of the surroundings increases.
Chemical reactions that absorb energy from the surroundings are described as endothermic
reactions. In an endothermic reaction the temperature of the surroundings decreases.
Describe bond breaking as an endothermic process and bond formation as an
exothermic process
A chemical reaction can be divided into 3 steps namely bond breaking, bond
rearrangement, and bond formation. Bond breaking requires energy. This energy is
required to break bonds; hence, bond breaking is endothermic. Bond formation releases
energy, hence, it is exothermic.
Heat energy and enthalpy change (ΔH) of reaction

When bonds are formed, heat energy is given out. The process is exothermic and ΔH
is negative.

When bonds are broken, heat energy is absorbed. The process is endothermic and ΔH
is positive.
Activation energy

Activation energy is the minimum energy required to initiate a reaction.

It is the energy needed to break the bonds in the reactant particles before new bonds
are formed.
Page 55 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Draw and label energy level diagrams for exothermic and endothermic reactions using
data provided
Interpret energy level diagrams showing exothermic and endothermic reactions and the
activation energy of a reaction
Chemical reactions
Rate of reaction
The rate of a reaction is the amount of a reactant used up per unit time
The amount of a product produced per unit time.
or
Describe practical methods for investigating the rate of a reaction which produces a gas
For reactions which produce gas, the gas can be collected using a graduated gas syringe. A
table of volume vs time is made and used to plot a graph. The time intervals can be every 10
seconds if the reaction is fast, or even minutes or hours if the reaction is slow.
Magnesium reacts with hydrochloric acid
to form magnesium chloride and hydrogen
gas. The rate of reaction can be followed by
noting the volume of hydrogen gas
collected in the gas syringe over a period of
time. When the volume becomes constant
(stops changing) it means the reaction has
reached completion.
Mg (s) + 2HCl (aq)→ MgCl2 (aq) + H2 (g)
Page 56 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
The rate changes
throughout the course of
the reaction. It is greatest
at the start, but decreases
as the reaction proceeds.
Interpret data obtained from experiments concerned with rate of reaction
Page 57 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
B
A
A: In terms of rate, A ˃ B ˃ C ˃ D
˃ E. At point E, gradient is zero
meaning that the rate is also zero,
so the reaction has
stopped/reached completion. The
graph/curve shows amount of
product formed with time.
B: In terms of temperature, curve
B shows a reaction carried out at a
higher temperature than that in
curve A. Notice that curve B‟s
mass becomes constant before
curve A‟s mass becomes constant.
Constant mass/volume indicates
the completion of a reaction.
C
C: In C, the answers are for 1) A
(more products formed) 2) C 3)
B (larger gradient per unit time
meaning higher rate)
Suggest suitable apparatus, given information, for experiments, including collection of
gases and measurement of rates of reaction
Measuring the change in mass of the reaction mixture
If the reaction produces a gas, we can use the set up
on the left. The mass reading drops as the gaseous
product is lost from the conical flask. When the
balance reading stops changing, it means the reaction
is over.
Alternatively, we can use the set up with the gas
syringe and take note of the volume of gaseous
product collected at fixed intervals of time. We would
need a flask, gas syringe and stop watch as some of
the apparatus.
1. Describe the effect of concentration, particle size, catalysts and temperature on
the rate of reactions
2. Describe and explain the effect of changing concentration in terms of frequency
of collisions between reacting particles
Page 58 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Effect of concentration on the rate of a reaction

Increase of concentration of either reactant A or B, or even both the reactants, means
there are more reactant particles per unit volume. The frequency of collisions between
the different reactant particles of reactant A and B increases, resulting in an increase
in the rate of the reaction.
Effect of temperature on the rate of a reaction

High temperatures increase the rate of a reaction by increasing the kinetic energy of
the reactant particles. This increases the frequency of collisions between different
reactant particles, leading to an increase in the rate of reaction.
Effect of particle size or surface area on the rate of a reaction
Decreasing the particle
size increases the surface
area of the particle. This
means a larger part of the
particle is exposed to the
surface and thus also
exposed to the other
reactant particles. A
powdered form of a
substance will thus react
faster than large lumps of
the same substance.
Remember: the smaller
the particle size, the
larger it’s surface area.
Page 59 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Effect of catalysts on the rate of a reaction

Catalysts are chemical substances which alter the speed of a reaction without being
used up at the end of a reaction.

Catalysts can either be enzymes (biological catalysts made up of proteins) or
transition metals and their compounds.

Transition metals (e.g. Nickel, Iron, Platinum) are good catalysts.

Most catalysts catalyse one kind of reaction i.e. they are specific. This is particularly
true for biological catalysts (enzymes)
Describe and explain the effect of changing temperature in terms of the frequency of
collisions between reacting particles and more colliding particles possessing the
minimum energy (activation energy) to react
Increasing temperature increases the kinetic energy of the particles in a system. This in turn
increases the frequency of collisions between reactant particles, leading to an increase in the
rate of the reaction. Additionally, only particles with energy equal to or greater than
activation energy are able to react to form products. Increasing temperature increases the
number of particles with this minimum energy requirement so that when they collide,
products are formed.
Redox
Describe oxidation and reduction in chemical reactions in terms of oxygen loss / gain
(Oxidation state limited to its use to name ions, e.g. Iron(II), Iron(III), Copper(II)).
Oxidation is the gain or addition of oxygen. Reduction is the loss or removal of oxygen. Iron
(III) means the ion of Iron has an oxidation state of 3 i.e. Fe 3+. The chemical formula of Iron
(III) oxide is thus Fe2O3.
Define and identify an oxidising agent as a substance which oxidises another substance
during a redox reaction and a reducing agent as a substance which reduces another
substance during a redox reaction
For the reaction
Fe2O3(s) + 3CO(g) → 2Fe(l) + 3CO2(g)
CO is oxidized to CO2
Fe2O3 is reduced to Fe
CO is the reducing agent
Fe2O3 is the oxidizing agent
Acids, bases and salts
The characteristic properties of acids and bases
1. Describe neutrality and relative acidity and alkalinity in terms of pH measured
using universal indicator.
Page 60 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
The pH scale states how acidic or alkaline a solution is by using a scale of numbers.
The numbers go from 0 to 14:
Universal indicator shows colours which can be used to stand for certain pH values.
Green is pH 7. It is neutral.
2. Describe the characteristic properties of acids (exemplified by dilute
hydrochloric acid and dilute sulfuric acid) including their effect on litmus paper
and their reactions with metals, bases and carbonates
Some commonly used acids are hydrochloric acid (HCl) and sulfuric acid (H2SO4). Acids
turn blue litmus paper red. Their characteristic reactions are as outlined below.
Chemical Properties of Acids
Dilute acids reactions with metals
Dilute acids react with metals that lie above hydrogen in the reactivity series. The reaction
produces salt and hydrogen gas.
zinc + dilute hydrochloric acid → zinc chloride + hydrogen
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
Copper does not react with dilute acids because it is less reactive than hydrogen.
Dilute acids reactions with bases. Soluble bases are called alkalis.
Acids react with bases to form salt and water. The base could be a metal oxide or hydroxide.
sodium hydroxide + dilute hydrochloric acid → sodium chloride + water
Page 61 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)
Dilute acids reactions with metal carbonates
Acids react with metal carbonates to produce salt, water and carbon dioxide.
calcium carbonate + dilute sulfuric acid → calcium sulfate + water + carbon dioxide
CaCO3(s) + H2SO4(aq) → CaSO4(aq) + H2O(l) + CO2(g)
Describe neutrality and relative acidity and alkalinity in terms of pH (whole numbers
only) measured using Universal Indicator
A pH indicator displays different colours at different pH values.
Universal Indicator is a mixture of pH indicators that gives different colours at different pH
values. The table below lists the different colours and the pH range at which they are
observed.
Summarized
as ROYGBV
Describe and explain the importance of controlling acidity in soil
Plants are sensitive to changes in soil pH. The pH levels can be controlled by adding certain
chemicals. For acidic soil, bases such as calcium oxide (quicklime) and calcium hydroxide
(slaked lime) can be added to neutralise the excess H+ ions from the acid. This process is
known as „liming‟. Care must be taken to avoid adding excess base as this would increase the
soil pH. This would make the soil too alkaline for plant growth.
Preparation of salts
1. Describe the preparation, separation and purification of salts
2. Suggest a method of making a given salt from suitable starting material, given
appropriate information
Preparation of salts
1. By reaction of a metal hydroxide and an acid
This method is suitable for soluble metal hydroxides called alkalis. The titration method is
used in this case. e.g.
Page 62 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
base + acid → salt + water
e.g. sodium hydroxide + hydrochloric acid → sodium chloride + water
sodium hydroxide + sulfuric acid → sodium sulfate + water







Usually 25.00 cm3 of acid is placed in a conical flask using a pipette.
Alkali is placed in the burette.
A few drops of indicator are added to the acid in the conical flask before it is titrated
with the alkali from the burette.
The indicator changes colour at some point as alkali is added to acid.
The change in colour shows the end of the titration.
The process is then repeated using the 25.00 cm3 of acid and the same volume of base
from the burette as used in the previous experiment, however, no indicator is used this
time.
Lastly, the solution obtained is crystallised to obtain the crystal salt.
2. By reacting metal with acid



This preparation method is suitable for metals like Mg, Al, Zn, Fe (but not K, Na and
Ca because these metals react vigorously with acids).
In general, excess metal is added to the acid until there is no further reaction (when no
more bubbles of hydrogen gas are produced).
Excess unreacted metal is then filtered out, and the clear filtrate is crystallized by
heating until a saturated solution is formed, and then leaving the saturated solution to
cool down and form crystals e.g.
zinc + sulfuric acid → zinc sulfate + hydrogen
Zn (s) + H2SO4 (aq) → ZnSO4 (aq) + H2(g)


Zn is added to dilute H2SO4 until it‟s in excess to ensure no more H2SO4 is present.
The mixture is then filtered to separate solid unreacted Zn from ZnSO4 solution.
Page 63 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section


The filtrate (ZnSO4) is then placed in an evaporating dish to evaporate most of the
water resulting in a saturated solution. The saturated solution is then left to cool down
so that ZnSO4 crystals begin to form.
The crystals are then filtered and dried by squeezing them between filter papers
Step 2
Step 1
Step 3
Step 4
3. By reacting metal oxide with acid



Nearly all metal oxides react with acids, but most require warming or heating.
This method is especially suitable for those metals which do not react with dilute
acids e.g. the metal copper.
Copper metal has no reaction with dilute acids but copper(II) oxide, if warmed with
dilute acids, forms salts.
copper (II) oxide + sulfuric acid →copper sulfate + water
CuO(s) + H2SO4 (aq) → CuSO4 (aq) + H2O (l)
Page 64 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section





Excess copper (II) oxide is added to warm sulfuric acid so that all the acid is
neutralised. The unreacted oxide is then removed by filtering.
The filtrate is a blue solution of copper (II) sulfate.
The crystals are obtained by concentrating the solution by evaporation, and then
leaving it to cool.
The crystals formed can be removed by filtration.
Since copper (II) sulfate crystals contain water of crystallisation, it is important not to
evaporate the solution to dryness because the water of crystallisation will be lost to
form powder.
4. By reacting metal carbonate with acid




This one is similar to the reaction involving metal oxide and acid, but this time, no
heating is required.
The carbonate fizzes and gives off carbon dioxide gas.
Excess metal carbonate must be added to ensure that all the acid is neutralised
The solution is then filtered (to remove unreacted carbonate) and then crystallized (by
heating up to saturation point and then leaving the solution to cool down).
e.g. Reacting CaCO3 with acids
calcium carbonate + sulfuric acid → calcium sulfate + carbon dioxide + water
CaCO3 (s) + H2SO4 (aq) → CaSO4 (aq) + CO2 (g) + H2O (l)


The same process is used as in the reaction of an acid with a metal; just that carbon
dioxide is also produced in this case.
Carbon dioxide can be tested by bubbling it into limewater. The limewater will
change from colourless to milky white.
Revision work
Element
symbol
Sodium
Potassium
Argon
Na
K
Ar
Nucleon
or mass
number
23
39
40
Number of
electrons
Number of
neutrons
Number of
protrons
11
19
18
12
20
22
11
19
18
Electronic
structure or
configuration
2.8.1
2.8.8.1
2.8.8
Page 65 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Describe and use the following tests to
Identify:
Aqueous cations: ammonium, calcium, copper (II), iron(II), iron(III) and zinc, by means
of aqueous sodium hydroxide and aqueous ammonia as appropriate (formulae of
complex ions are not required).
Tests for aqueous cations
Cation
Ammonium (NH4+)
Calcium (Ca2+)
Copper (Cu2+)
Iron (II) (Fe2+)
Iron (III) (Fe3+)
Zinc (Zn2+)
Effect of adding aqueous
sodium hydroxide
Ammonia produced on
warming
White ppt, insoluble in
excess
Light blue ppt, insoluble in
excess
Green ppt, insoluble in
excess
Red brown ppt, insoluble in
excess
White ppt, , soluble in excess
giving a colourless solution
Effect of adding aqueous
ammonia
_
no ppt. or very slight white
ppt.
light blue ppt., soluble in
excess,
giving a dark blue solution
green ppt., insoluble in
excess
red-brown ppt., insoluble in
excess
white ppt., soluble in excess,
giving a colourless solution
Cations: flame tests to identify lithium, sodium, potassium and copper (II)
Flame tests
Metal ion
Lithium (Li+)
Sodium (Na+)
Potassium (K+)
Copper (II) (Cu2+)
Flame colour
Red
Yellow
Lilac
Blue-green
Anions: carbonate (by reaction with dilute acid and then limewater), chloride (by
reaction under acidic conditions with aqueous silver nitrate), nitrate (by reduction with
aluminium) and sulfate (by reaction under acidic conditions with aqueous barium ions)
Page 66 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Tests for anions
Anion
Carbonate (CO32-) [in solution]
Test
Add dilute acid
Chloride (Cl-)
Add dilute nitric acid,
then add aqueous silver
nitrate
Add aqueous sodium
hydroxide, then
aluminium foil: warm
the mixture carefully
Acidify (add acid), then
add aqueous barium
nitrate
[in solution]
Nitrate (NO3-) [in solution]
Sulfate (SO42-)
[in solution]
Test result
Effervescence, carbon
dioxide produced
White ppt (precipitate)
formed
Ammonia produced
White ppt formed
Gases: ammonia (using damp red litmus paper), carbon dioxide (using limewater),
chlorine (using damp litmus paper), hydrogen (using a lighted splint), oxygen (using a
glowing splint)
Tests for gases
Gas
Ammonia (NH3)
Carbon dioxide (CO2)
Chlorine (Cl2)
Hydrogen (H2)
Oxygen (O2)
Test and test result
Turns damp red litmus paper blue
Turns lime water milky
Bleaches damp litmus paper
„pops‟ with a lighted splint
Relights a glowing splint
The Periodic Table
Describe the Periodic Table as a method of classifying elements and its use to predict
properties of elements
A periodic table is used to classify elements by placing them in groups (elements whose
atoms have the same outer most electrons are placed in the same group) and periods
(elements whose atoms have the same number of shells are placed in the same period).
Elements with the same outermost electrons have the same or similar chemical properties e.g.
group one elements react similarly with water to form hydroxides.
Page 67 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Periodic trends
Describe the change from metallic to non metallic character across a period
A trend is a pattern. One trend found in the periodic table is that from left to right, elements
gradually change from metals to non-metals. Metals are generally found to the left of the
periodic table, and non metals are found to the right. Metalloids are elements that have both
the characteristics of metals and non metals. You need not worry about these for now.
Describe and explain the relationship between Group number, number of outer shell
electrons and metallic/non-metallic character
The period number corresponds to the number of electron shells present in an atom of an
element. An element in period 2 has 2 electron shells.
The relationship between number of shells and period number
Element
Helium
Sodium
Magnesium
Lithium
Electronic
configuration
2
2,8,1
2,8,2
2,1
Period
Number of shells
1
3
3
2
1
3
3
2
Page 68 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Group properties
1. Describe lithium, sodium and potassium (elements in Group I) as a
collection of relatively soft metals showing a trend in melting point,
density and reaction with water
2. Predict the properties of other elements in Group I, given data, where
appropriate
Elements in Group I are known as alkali metals. The atoms of these elements have one
electron each in the outermost shell. These metals are soft and can be cut easily with a knife.
These metals show a trend (pattern) in melting point, density and reaction with water. You
are expected to be able to predict the behavior of an element in group one when given the
behavior of other elements in that group.
Moving down the group, the melting and boiling points decrease while the densities increase.
Moving down the group, the reaction of these metals with water increases.eg. the element
lithium (which is above sodium and potassium in group 1) has a higher melting and boiling
point than potassium; lower density than potassium; and reacts less with water as compared
to potassium.
Describe the halogens, chlorine, bromine and iodine in Group VII, as a collection of
diatomic non-metals showing a trend in colour and physical state
The group VII elements are known as the halogens. These include the elements chlorine,
bromine and iodine. Group VII elements exist as diatomic molecules (e.g. Cl2, Br2, l2). Di
means two, hence, diatomic molecules are molecules formed by joining two atoms of the
same element together. Group VII is found to the right of the periodic table; hence, elements
in this group are non-metals. Group VII elements show a trend (pattern) in colour and
physical state. The trend in colour is that the colour darkens down the group (Chlorine is a
yellow-green gas, bromine is a reddish-brown liquid and iodine is a black solid). The trend in
physical state is that the elements change from gas to liquid and from liquid to solid as we go
down Group VII (Chlorine is a gas, bromine is a liquid and iodine is a solid).
1. State the reaction of chlorine, bromine and iodine with other halide ions
Halogens at the top of the group are more reactive than those below them. Halogens undergo
displacement reactions, where a more reactive halogen displaces a less reactive halogen from
its salt. For instance, when chlorine gas is bubbled into sodium bromide solution, bromide
ions get displaced.
Cl2(g) + 2NaBr(aq) → 2NaCl(aq) + Br2(aq)
Generally, chlorine can displace both bromine and iodine. Bromine can displace iodine only.
Iodine cannot displace either chlorine or bromine because they are above it in Group VII.
Page 69 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
2. Predict the properties of other elements in Group VII, given data where appropriate
To predict the trend, simply remember that halogens are non-metals showing a trend in
colour and physical state. An element below Iodine would have to exist as a solid.
3. Identify trends in other groups, given data about the elements concerned
To identify the trend in the group, simply make sense of the pattern in the group.
Transition elements
Describe the transition elements as a collection of metals having high densities, high
melting points and forming coloured compounds, and which, as elements and
compounds, often act as catalysts
Transition elements are a block of metals found between Groups II and III in the Periodic
Table. These metals have high melting and boiling points, as well as high densities.
Compounds of transition elements are usually coloured. Compounds are formed when two or
more elements react together to form one product (known as a compound). One of the
elements reacting to form a compound, in this case, would be a transition element.
Transition elements and their compounds are good catalysts. Catalysts are substances which
speed up the rate of a chemical reaction. They make us obtain the products of the reaction in
a much shorter time. Examples of transition metals include iron (Fe), copper (Cu), and
vanadium (V). Check where they are located on your periodic table.
Noble gases
Describe the noble gases, in Group VIII or 0, as being unreactive, monoatomic gases
and explain this in terms of electronic structure
Elements in Group VIII (or sometimes referred to as Group 0) are known as noble gases.
These elements are inert (inert simply means unreactive) non-metals which are found as
monoatomic gases. Monoatomic means the atoms of these elements exist as single gaseous
atoms. (Remember that the halogens, unlike the noble gases, exist as diatomic molecules).
Their lack of reactivity is due to their complete shell of valence or outermost electrons (that
is, their electronic structure is such that all the shells are full or contain the maximum
possible number of electrons). Due to their unreactive nature, noble gases are often used to
provide an inert atmosphere. The following table shows some uses of noble gases. You need
to remember these uses.
State the uses of the noble gases in providing an inert atmosphere, i.e. argon in lamps,
helium for filling balloons
Element
Helium
Argon
Application
filling balloons
Light bulbs
Page 70 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Metals
Properties of metals
1 Describe the general physical properties of metals as solids with high melting and
boiling points, malleable and good conductors of heat and electricity
Metals are solids which are good conductors of electricity
and heat.
Metals are solids with high melting and boiling points since
a lot of energy is required to break the strong electrostatic
forces of attraction between the „sea of delocalized electrons‟
and the lattice of positive ions.
Metals are malleable which means that metals can be shaped
by hammering.
The diagram to the left shows metallic bonding.
2 Describe alloys, such as brass, as mixtures of a metal with other elements
An alloy is a mixture of a metal and other elements, which may be metals or non-metals.eg.
brass is an alloy made by mixing the metals copper and zinc.
3 Explain in terms of their properties why alloys are used instead of pure metals
Turning a metal into an alloy changes its properties, and makes it more useful.
A pure metal is soft due to the regular arrangement of atoms in the metal lattice. The atoms
are arranged in layers which slide past each other easily when a force is applied.
In an alloy, however, the regular arrangement of atoms is disrupted by the presence of atoms
of different sizes (since an alloy has atoms of different elements in it and these atoms of
different elements also differ in size). This prevents the layers of atoms from easily sliding
over each other, making the alloy harder than the pure metal.
Page 71 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
4 Identify representations of alloys from diagrams of structure
Alloying metals helps to change
their properties to make them
more suitable for a particular
use. For instance, an alloy of
iron and chromium has greater
resistance to rusting compared to
pure iron.
Reactivity series
Carbon and hydrogen are not metals but are placed due to their characteristic reactions with
metals. To remember the above elements in the reactivity series, master the phrase “Please
Stop Calling Me A Careless Zulu. I‟m Highly Complex”. Reactivity decreases from
potassium to copper.
Part of phrase
Element
Please
Potassium
(most reactive)
Stop
Sodium
Calling
Calcium
Me
Magnesium
A
Aluminium
Careless
Carbon
Zulu
Zinc
I‟m
Iron
Highly
Hydrogen
Complex
Copper
(least reactive)
1 Place in order of reactivity: potassium, sodium, calcium, magnesium, aluminium,
(carbon), zinc, iron, (hydrogen) and copper, by reference to the reactions, if any, of the
elements with:
 water or steam
Remember that carbon and hydrogen are not metals so they do not react with water or steam.
Reactivity of the above metals with water decreases from potassium to iron. From the list,
only copper does not react with both water and dilute acids. The metals potassium to iron
react with water to form the metal oxide and hydrogen gas. The metals actually displace the
hydrogens in a water molecule, and inturn form a bond with the oxygen which had previously
been bonded to the displaced hydrogen. The hydrogen is then displaced as hydrogen gas.
Metals also displace hydrogen in dilute hydrochloric acid (HCl(aq) ), and inturn bond with the
chlorine of the hydrochloric acid to form chlorides (certain salts)
 dilute hydrochloric acid
The metals potassium to iron react with dilute hydrochloric acid to form the metal chloride
and hydrogen gas. Copper does not react with either water and dilute hydrochloric acid
(remember this!) because if you check the reactivity series above, copper is less reactive than
Page 72 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
hydrogen, hence, it cannot displace hydrogen. Thats why if we need to make a salt of copper,
we react copper oxide with dilute acids, and not copper with dilute acids (since these two do
not react together!!!!). Reactions of metals with either water or dilute hydrochloric acid are
displacement reactions where by hydrogen in the water or acid is displaced by a more
reactive metal.
The reactivity series is like the world heavy weight boxing championships where by the
elements are fighting to wear the belt (either oxygen if reacting with water, or chlorine if
reacting with dilute acid). These elements need to displace the sitting champion (hydrogen in
this case). Only those elements ranked above hydrogen will displace it. Take note that carbon
is not a metal so it won‟t displace hydrogen, and also that hydrogen cannot displace itself
because if hydrogen displaces hydrogen then the overall change is zero.
 reduction of their oxides with carbon
Metals are usually found in nature as ores, which mainly consist of metal oxides. The
extraction of a metal from its ore depends on its reactivity. A more reactive metal usually
requires tougher methods of extraction compared to a less reactive metal. Only Zinc, Iron and
copper can be extracted from their oxides through heating with carbon. All these metals are
below carbon in the reactivity series.
2 Describe the reactivity series in terms of the tendency of a metal to form its positive
ion, illustrated by its reaction, if any, with the aqueous ions of other listed metals
Reactive metals easily form positive ions by easily losing electrons. When a more reactive
metal is placed in a solution containing aqueous ions of a less reactive metal eg. when
calcium is placed in a solution containing aqueous ions of copper metal, the calcium metal
will form calcium aqueous positive ions by losing its outer two electrons. These electrons are
picked up by the aqueous ions of the less reactive metal, and convert those ions to metal
atoms.
calcium metal + copper nitrate → calcium nitrate + copper metal
However, no reaction occurs when a less reactive metal is placed in the salt solution of a
more reactive metal. No change is seen when copper metal is placed in magnesium sulfate
solution since magnesium is more reactive than copper.
Extraction of metals from their ores
1 Describe the use of carbon in the extraction of copper from copper oxide
Copper can be extracted from copper oxide by heating copper oxide with carbon. The word
equation is:
Copper oxide + carbon → copper + carbon monoxide
or
Copper oxide + carbon → copper + carbon dioxide
Page 73 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
2 Describe and explain the essential reactions in the extraction of iron from hematite in
the blast furnace
 C + O2 → CO2
 C + CO2→ 2CO
 Fe2O3 + 3CO → 2Fe + 3CO2
Extraction of Iron
The blast furnace is used to extract iron from its iron ore called haematite, Fe2O3. A mixture
of iron ore, coke and limestone, known as the charge, is added at the top of the blast furnace.
Hot air is pumped into the blast furnace via ports at the bottom of the furnace.
Chemical processes which take place in the blast furnace
 Oxygen in the air reacts with coke (carbon) to give carbon dioxide. The reaction is
exothermic (gives out heat) and gives rise to the high temperatures experienced in the
blast furnace.
C(s) + O2(g) → CO2(g)
 The carbon dioxide produced (above) then reacts with more coke to produce carbon
monoxide
CO2(g) + C(s) → 2CO(g)
 The carbon monoxide then reacts with iron (III) oxide to produce molten iron
3CO(g) + Fe2O3(s) → 2Fe(l) + 3CO2(g)
Page 74 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
3 Know that aluminium is extracted from the ore bauxite by electrolysis
Aluminium is extracted from its ore, bauxite, by electrolysis. It cannot be extracted by
heating with carbon because its more reactive than carbon (above carbon in the reactivity
series).
4 Relate the method of extraction of a metal from its ore to its position in the reactivity
series
The extraction of a metal from its ore depends on its reactivity. A more reactive metal usually
requires tougher methods of extraction compared to a less reactive metal.
Zinc, Iron and copper (all below carbon in the reactivity series) can be extracted from their
oxides through heating with carbon. The carbon reduces the oxides to give the metals.
Aluminium and other metals above it in the reactivity series form very stable oxides that are
not easily reduced by Carbon. They can only be extracted from their ores through electrolysis
of their molten oxides. Generally, metals above carbon are extracted by electrolysis and
those below are extracted by reduction with carbon.
5 Describe metal ores as a finite resource and hence the need to recycle metals
Metal ores are a finite resource i.e. they are limited in the earth‟s crust. Hence, for
sustainability, scrap metal should be recycled.
Air and water
Water
1 Describe a chemical test for water using copper (II) sulfate and cobalt (II) chloride
Test for water:
 Water turns white copper (II) sulfate (CuSO4) blue.
 Water turns blue Cobalt (II) chloride (CoCl2) pink
2 Describe, in outline, the treatment of the water supply in terms of filtration and
chlorination
1. Filtration
The water is filtered to remove suspended particles and unsettled floc. Slow sand filters can
be used since the water must be passed very slowly through the filters. The filters are
constructed using graded layers of sand, with the finest sand at the top and the coarsest sand
(along with some gravel) at the bottom. Drains at the base of the filters convey filtered water
away for disinfection.
2. Disinfection
Disinfection is achieved by adding chlorine or one of its compounds. The chlorine kills
harmful organisms because of its strong oxidative properties.
Page 75 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Air
1 State the composition of clean air as being a mixture of 78% nitrogen, 21% oxygen
and small quantities of noble gases, water vapour and carbon dioxide
Composition of air
Clean air is composed of 21% Oxygen, 78% Nitrogen and small quantities of noble gases,
water vapour and carbon dioxide.
2 Name the common pollutants in air as being carbon monoxide, sulfur dioxide and
oxides of nitrogen
Common pollutants in air are carbon monoxide, sulfur dioxide and oxides of nitrogen. Oxides
of nitrogen are nitrogen monoxide and nitrogen dioxide.
3 State the adverse effect of these common air pollutants on buildings and on health
Oxides of nitrogen and sulfur dioxide lead to acid rain. The acid rain corrodes buildings made
of marble and limestone. Sulfur dioxide causes respiratory problems in humans.
Oxides of nitrogen irritate lung tissues and the eyes.
Carbon monoxide reduces the ability of haemoglobin to carry oxygen. This deprives cells of
oxygen, leading to headaches, fatigue or even death.
4 State the conditions required for the rusting of iron (presence of oxygen and water)
The conditions required for the rusting of iron are the presence of oxygen and water. In the
absence of either one of these two, rusting will not occur.
5 Describe and explain barrier methods of rust prevention, including paint and other
coatings
Barrier methods of rust prevention are methods which reduce oxygen and water from
coming into contact with iron. They place a barrier between iron, and both water and oxygen.
Page 76 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Rusting can be prevented by
1. Painting or covering the metal with a layer of oil. This protects iron from being
exposed to oxygen and water.
2. Sacrificial protection. In this method, a more reactive metal is used as the sacrificial
metal and corrodes/rusts instead of iron. This is usually done by attaching a block of
magnesium or zinc to the iron.
3. Galvanizing Iron (coating of iron with zinc). The zinc coating keeps air and water (in
the form of moisture) away. However, if the coating gets damaged, the zinc will still
protect the iron by sacrificial protection.
Carbon dioxide and methane
1 State the formation of carbon dioxide as follows:
Carbon dioxide is a product in the following processes
1.
2.
3.
4.
complete combustion of carbon-containing substances
respiration
the reaction between an acid and a carbonate
thermal decomposition of calcium carbonate
2 State that carbon dioxide and methane are greenhouse gases
The greenhouse effect which is caused by greenhouse gases leads to global warming.
Examples of greenhouse gases are carbon dioxide and methane.
3 State that increased concentrations of greenhouse gases cause an enhanced
greenhouse effect, which may contribute to climate change
When greenhouse gases are produced faster than they are removed from the atmosphere (eg
by processes like photosynthesis), an accumulation of these gases in the atmosphere results.
This accumulation causes of greenhouse gases causes global warming. Global warming refers
to an increase in global temperatures due to high levels of greenhouse gases. This global
warming may contribute to climate change, cause drought or cause flooding.
Organic chemistry
Fuels
1 State that coal, natural gas and petroleum are fossil fuels that produce carbon dioxide
on combustion
Coal, natural gas and petroleum are fossil fuels that produce carbon dioxide on combustion.
2 Name methane as the main constituent of natural gas
Natural gas is a mixture of substances. The main constituent of natural gas is methane.
Page 77 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
3 Describe petroleum as a mixture of hydrocarbons and its separation into useful
fractions by fractional distillation
Petroleum is a mixture of hydrocarbons which can be separated into various useful fractions
by fractional distillation.
4 Describe the properties of molecules within a fraction
Petroleum consists of hydrocarbons that have different boiling points and condense at
different temperatures.
Higher parts of the fractionating column have lower temperatures while lower parts of the
fractionating column have higher temperatures.
Since lighter fractions have lower boiling points, they are tapped off at higher parts of the
column. Heavier fractions on the other hand, have higher boiling points and are tapped off at
lower parts of the column. Generally, the molecules of fractions at the top have
1.
2.
3.
4.
5.
lower boiling point
smaller molecules
weaker intermolecular/attractive forces
greater flammability
and lower viscosity…as compared to those at the bottom
A simplified diagram of the fractional distillation of petroleum and the fractions collected is
shown below.
5 Name the uses of the fractions as follows:
Uses of the fractions of petroleum





refinery gas: used as „bottled gas‟ for heating and cooking
gasoline fraction: used as a fuel (petrol) in cars
naphtha fraction: used as a feedstock for making chemicals
diesel oil: used as a fuel in diesel engines
bitumen: used in making road surfaces
Page 78 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Homologous series
1 Describe the homologous series of alkanes and alkenes as families of compounds with
the same general formula and similar chemical properties
A homologous series is a family of organic compounds with the same general formula and
similar chemical properties.
Alkanes and alkenes are two examples of a homologous series.
Alkanes
1 Describe alkanes as saturated hydrocarbons whose molecules contain only single
covalent bonds
Alkanes are referred to as saturated hydrocarbons because their molecules contain only single
covalent bonds. Note that a hydrocarbon contains hydrogen and carbon only!!!!
Substances made
up of larger
molecules have
greater
intermolecular
attractive forces
acting between
their molecules,
giving rise to
greater melting and
boiling points e.g
octane, which
seems to have the
largest molecules,
has the highest
m.p and b.p
2 Describe the properties of alkanes (exemplified by methane) as being generally
unreactive, except in terms of burning

alkanes do not react with most chemicals since they are saturated, thus having only
C-C and C-H single covalent bonds.

Alkanes , however, undergo burning or combustion.
3 Describe the complete combustion of hydrocarbons to give carbon dioxide and water
Hydrocarbons undergo complete combustion to give carbon dioxide and water. A lot of heat
energy is also given out.
Page 79 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
Alkenes
1 Describe alkenes as unsaturated hydrocarbons whose molecules contain one double
covalent bond
Alkenes are referred to as unsaturated hydrocarbons because their molecules contain one
double covalent bond between two Carbon atoms.
e.g. ethene
2 State that cracking is a reaction that produces alkenes
Alkenes are made from a process called cracking
3 Describe the formation of smaller alkanes, alkenes and hydrogen by the cracking of
larger alkane molecules and state the conditions required for cracking
Large alkane molecules can be broken down into smaller molecules through cracking. This
process requires the following conditions
1. a catalyst (either aluminium oxide or silicon dioxide).
2. High temperatures or heating.
Examples of
cracking. You do not
need to remember the
names of the
complex molecules.
Note that the total number of carbon and hydrogen atoms on the left side is equal to the total
number of carbon and hydrogen atoms on the right. This is because matter is neither created
nor destroyed; it is simply converted from one form to another. This is known as the law of
conservation of matter. Decane (above) has 10 carbon atoms and 22 hydrogen atoms.
Pentane, propene and ethene (the products of the cracking of decane) also have a sum of 10
carbon atoms and 22 hydrogen atoms.
Page 80 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Chemistry section
4 Recognise saturated and unsaturated hydrocarbons:
 from molecular structures
Two unsaturated structures are shown below. Notice the presence of C to C double bonds.
For saturated structures study the
structures of the alkanes given on
previous pages of these notes.
 by their reaction with aqueous bromine
Aqueous bromine reacts with substances which have a C = C bond (alkenes).
The addition of aqueous bromine is thus used in testing whether a substance is a saturated or
unsaturated compound. Aqueous bromine is reddish-brown. When added to an unsaturated
compound ( alkene) it changes from reddish-brown to colourless. There is no colour change
when reddish-brown aqueous bromine is added to a saturated compound (alkane).
5 Describe the formation of poly(ethene) as an example of addition polymerisation of
monomer units
Just as bricks can be used to make houses in a process called building, monomers can be used
to build a polymer in a process called polymerization.
Many ethene molecules can be added together to form a polymer called poly(ethene). The
word mono means one…..the word poly means many…..
The formation of poly(ethene) is an example of addition polymerisation of monomer units
Note that there are no C to C double bonds in polythene
Page 81 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Motion
Length and time
1 Use and describe the use of rules and measuring cylinders to find a length or a volume
Rules are used to measure length. A metre rule is ideal for measuring lengths up to 100 cm. it
has an accuracy of up to 0.1cm.
When using a metre rule one must be careful to avoid parallax error (an error due to reading
from an angle) by making readings at eye level.
How to avoid errors by
a. correct positioning of the eye
b. making sure the object touches the marking of the scale (for
measuring tape and metre rule, ensure that the object is in contact
with the scale)
(a) Precision is how close the measured values
are to each other.
(b) Accuracy is how close a reading is to the true
value of the measurement. The accuracy of a
reading can be improved by repeating the
measurements.
Page 82 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Volume is measured using burettes, pipettes, measuring cylinders, volumetric flasks and
beakers. Measuring cylinders measure a wide range of volumes whilst pipettes and
volumetric flasks are designed with one marking only to measure a single specific volume.
When using measuring
cylinders and burettes, one
must be careful to avoid
parallax error (an error due to
reading from an angle) by
making readings at eye level.
2 Use and describe the use of clocks and devices, both analogue and digital, for
measuring an interval of time
Clocks and stop watches are used for measuring an interval of time.
Nowadays digital stopwatches are being used rather than analogue ones because analogue
stopwatches are prone to parallax error. However, starting and stopping of stopwatches
manually for time interval measurements results in error due to reaction time.
3 Obtain an average value for a small distance and for a short interval of time by
measuring multiples (including the period of a pendulum)
When asked to make measurements e.g. measuring distance or time, make more than one
measurement and calculate the average.
Making multiple measurements and calculating their average reduces error and increases
accuracy.
Motion
1 Define speed and calculate average speed from
𝒕𝒐𝒕𝒂𝒍 𝒅𝒊𝒔𝒕𝒂𝒏𝒄𝒆
𝒕𝒐𝒕𝒂𝒍 𝒕𝒊𝒎𝒆
Speed is the change of distance with time. It is measured in metres/second (m/s) or
kilometres/hour (km/h).
Average speed is calculated by dividing the total distance travelled by the time taken
Page 83 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Speed =
𝑡𝑜𝑡𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒
𝑡𝑜𝑡𝑎𝑙 𝑡𝑖𝑚𝑒
2 Plot and interpret a speed-time graph and a distance-time graph
3 Recognise from the shape of a speed-time graph when a body is:
 at rest
 moving with
constant (steady)
speed
 moving with
changing speed
The speed-time graph of a moving object is used to find:
(a) Acceleration (using the gradient of graph)
(b) Distance travelled (using the area under the graph)
An increase in speed is a positive acceleration, a decrease in speed is a negative
acceleration / deceleration / retardation.
• If acceleration is not constant, the speed/time graph will be curved.
• The downwards acceleration of an object is caused by gravity. This happens most when an
object is in free fall (falling with nothing holding it up). Objects are slowed down by air
resistance
4 Calculate the area under a speed-time graph to work out the distance travelled for
motion with constant acceleration
5 Calculate acceleration from the gradient of a speed-time graph
6 Recognise linear motion for which the acceleration is constant (uniform) and calculate
the acceleration
Page 84 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
7 Recognise motion for which the acceleration is not constant (or uniform)
The area under a speed-time graph gives the distance. Acceleration is calculated from the
gradient of a speed-time graph
1
1
Total distance travelled = 2 base × height = 2 4 × 8 = 16m
Distance travelled from t = 3 to t = 4 is = area of shaded
region = area of triangle part + area of rectangle part =
1
(2 1 × 2) + (6 × 1) = 1 + 6 = 7
Acceleration =
𝑐𝑕𝑎𝑛𝑔𝑒 𝑜𝑓 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦
𝑡𝑖𝑚𝑒
Gradient of the graph =
8−0
4−0
=
= 2ms-2
For an object moving with constant acceleration, the speed-time graph is a sloping straight
line. A constant acceleration means that speed is increasing at a constant rate.
For graphs showing non uniform acceleration (two graphs below), acceleration can be
calculated for a particular time by drawing a tangent on the curve and calculating its gradient
Page 85 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Summary of some graphs
In the diagram to the left, lines a,b and c
represent different gradients/steepness. Line "a"
is the steepest therefore it has a higher average
speed than the rest and "c" has the lowest
average speed.
Graph-d:
The graph is getting less steep, hence, speed is decreasing. Decreasing speed is called
deceleration or retardation. Hence, the object is retarding or decelerating.
Graph-e:
When you throw something up, it goes against gravity because the force of gravity is pulling
it down. This constant downward pull of gravity reduces the speed per unit time therefore the
gradient of the graph keeps falling; that's why the object has a deceleration graph.
Graph-f:
Gravity pulls every object downwards therefore the presence of a constant force increases the
speed of the falling object. The speed is highest just before reaching the ground. Increasing
speed is called acceleration.
Page 86 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Example 1
A model train travels between two stations. The velocity–time graph shows the train's
motion.
(a) (i) State in which part of the journey A, B or C the train is decelerating. [C]
(ii) Explain your answer. [-ve gradient]
(iii) What does the graph show about the deceleration? [constant deceleration]
(b) (i) What feature of the graph represents the distance travelled between the two
stations? [Area under the graph]
Example 2
(a) A student walks from home to a library, waits to collect a book and then runs to a
friend's house. The distance-time graph for the student is shown. Three sections of the graph
are
labelled P, Q and R. Complete the sentences with P, Q or R.
(i) The student is walking at constant speed in section .............................................(1)
(ii) The student is waiting at the library in section ...............................................(1)
(iii) The two sections of the graph that take equal amounts of time are........... and .............(1)
(b) Use words from the box to complete the sentences. You may use each word once, more
than once or not at all.
Page 87 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
(i) My answer to (ai) is because the section of the graph is ....... and .......... (2)
(ii) My answer to (aii) is because the section of the graph is.....................................(1)
(c) How does the graph show that the student's friend lives nearer to the library than the
student does?
Example 2 Answers ai) P; aii) Q; aiii) Q and R; bi) Sloping straight; bii) Horizontal; c)
Less distance travelled in section R than in section P
8 Demonstrate an understanding that acceleration and deceleration are related to
changing speed including qualitative analysis of the gradient of a speed-time graph
[objective covered above]
Mass and weight
1 Distinguish between mass and weight
Weight, unlike mass, is a force. Weight and mass are related by the equation
Weight = mass × acceleration due to gravity
Mass
Weight
The property of an object that is a measure of
The force of gravity acting on an object,
measured in Newtons, and given by the
formula:


its inertia (defined as the resistance of
a body to change its state of rest or
motion due to its mass),
Weight = mass × acceleration due to gravity
the amount of matter it contains
The more the mass, the heavier the object, therefore, the object is more difficult to move. It's
difficult to move a heavy truck than a bicycle. Mass resists the change from rest to motion.
However, it is equally difficult to stop the motion of a heavy object than a lighter one. This
property of mass by which it can resist the change from rest to motion and motion to rest is
called inertia. The greater the mass, the more the inertia.
2 Know that the Earth is the source of a gravitational field
The source of the gravitational field is the earth
Page 88 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
3 Describe, and use the concept of, weight as the effect of a gravitational field on a mass
Since Weight = mass × acceleration due to gravity,
Weight can be described as the effect of a gravitational field on a mass.
4 Recognise that g is the gravitational force acting on a unit mass and is measured in N /
kg
5 Recall and use the equation W = mg
Weight = mass × acceleration due to gravity
W = mg
𝑾
hence, g = 𝒎
Since W is a force known as the gravitational force, g is the gravitational force acting on a
unit mass, and is measured in N / kg
Density
1 Recall and use the equation ρ =
𝒎
𝑽
𝒎𝒂𝒔𝒔
Density = 𝒗𝒐𝒍𝒖𝒎𝒆 using symbols, ρ =
𝒎
𝑽
The density of 1 kg of iron is the same as the density of 2 kg of iron because density of every
material stays the same.
Worked Example, (calculating density of regular shaped objects)
A gold bar of mass = 5 kg has length = 5 cm, width = 15 cm and height = 10 cm. Find
density.
Solution: To calculate density we need to measure the volume of the bar; but before we do
that, we need to convert it into meters so L = 0.05 m, W = 0.15 m and H = 0.10 m
Volume = L x W x H = 0.05 x 0.15 x 0.10m3= 0.00075m3
Density = mass / volume = 5 / 0.00075 = 6667kgm-3
2 Describe an experiment to determine the density of a liquid and of a regularly shaped
solid and make the necessary calculation
For the density of a liquid
 find the mass of a certain volume of liquid e.g. 10cm3
 divide that mass by the volume to find density
Page 89 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
For the density of a regularly shaped solid
 calculate the volume of the object mathematically e.g. if it‟s a rectangular prism use
length × width × height
 find the mass of the object using a beam balance
 divide the mass by the mathematically calculated volume to find the density
3 Describe the determination of the density of an irregularly shaped solid by the method
of displacement and make the necessary calculation
For the density of an irregularly shaped solid eg. a rock
 find the volume of the object by the method of displacement in a measuring cylinder.
This is done by placing a certain volume of water in a measuring cylinder and noting
its initial volume. The irregularly shaped object is then placed in the same measuring
cylinder where it will displace some of the water to give a new volume reading. The
difference between the two volume readings is equal to the volume of the irregularly
shaped solid.
 find the mass of the solid using a beam balance.
 divide the mass by the volume of the solid to get density
A speed time graph
The volume of regularly shaped solids can be calculated using mathematical formulas instead
of the displacement method. The displacement method (described above) is ideal for irregular
solid objects because we cannot calculate their volumes mathematically. Examples of regular
shaped objects are spherical objects and rectangular prisms.
Volume for rectangular prisms = length × width × height
Page 90 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Effects of forces
1 Describe how forces may change the size, shape and motion of a body
A force may produce a change in size and shape of a body; cause acceleration or deceleration
or a change in direction depending on the direction of the force.
2 Plot and interpret extension-load graphs and describe the associated experimental
procedure
1. set up apparatus
i.e hang spring
2. measure initial
length of spring
4. measure new
length and
subtract initial
length to calculate
extension
3. add 100g mass
5. repeat 6 times,
adding 100g
masses each time.
6. plot extension
against load
3 State Hooke‟s Law and recall and use the expression F = k x, where k is the spring
constant
Hooke‟s Law states that springs extend in proportion to load, as long as they are under their
limit of proportionality. The proportional limit is the region when the graph ceases to be a
straight line.
Load (N) = spring constant (N/mm) x extension (mm)
F=kx
4 Recognise the significance of the term „limit of proportionality‟ for an extension-load
graph
The limit of proportionality is the point above which the load and extension would no longer
be directly proportional.
The elastic limit is the point above which the spring will not return to its original shape after
being stretched
Page 91 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Hooke's law is only valid for straight line parts of the graph, i.e up to the limit of
proportionality where force and extension are directly proportional. Beyond the limit of
proportionality, Hooke's law is not valid. The elastic limit is beyond the limit of
proportionality.
The material, up to the elastic limit, is able to retain its
shape e.g. if a spring is stretched, it would be able to
go back to its original shape when the force is
removed. We say that the material is in an elastic
region. If the spring is stretched too much i.e a large
force is applied, the spring won‟t be able to return
back to its original shape, it will become elongated
forever. We say that the spring is now in the plastic
region. All materials (copper, iron, rubber etc) behave
in the same way as springs; they extend on the
application of a force and return back to their original
length upon its removal. However, if the force is large,
all materials deform permanently (plastic
deformation).
5 Understand friction as the force between two surfaces which impedes motion and
results in heating
Friction is the force between two surfaces which impedes motion and results in heating
6 Recognise air resistance as a form of friction
Air resistance is a form of friction because it impedes (opposes) motion.
7 Find the resultant of two or more forces acting along the same line
Page 92 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
8 Recognise that if there is no resultant force on a body it either remains at rest or
continues at constant speed in a straight line
Newton‟s first law of motion states that a body will continue in its present state of rest or
uniform motion unless if acted on by an external force.
Example:
(a) Complete the sentence.
Hooke's law states that a force acting on a material produces an extension which is
............................................................. to the force.
(1)
(b) A student attaches a load to the end of a spring.
(i) Name the type of force acting in the stretched spring.
(c) A force–extension graph for rubber is shown. Three regions A, B and C are
labelled.
Answers:
a-(directly) proportional
b-(i) tension /weight / gravitational
force
c-(i) A
(ii) B
(iii) large extension for small increase
in force
(i) In which region is Hooke's law obeyed?
(ii) In which region is the rubber easiest to extend?
(iii) Explain your answer to (ii)
(Total 7 marks)
Page 93 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Pressure
1 Relate qualitatively pressure to force and area, using appropriate examples
2 Recall and use the equation p = F / A
Pressure = force / area
Force is a numerator and area is a denominator. If force is large and area is small then the
pressure would be bigger and vice versa.
If Force = 5 N and area is 5 m2
then pressure is P = 5/5 = 1 N/m2 or Pascal
However, if force = 5 N and area is 0.5 m2 then pressure would be P = 5 / 0.5 = 10 N/m2
That‟s why camels can walk on the desert but a beautiful lady with high and sharp heels
cannot. Reason, camel's feet are wide so the area is large and the camel's weight is divided
between the four wide legs. However, the beautiful lady's weight is divided only between the
two feet whose contact area with the ground is very small due to sharp heels.
Example#1: An elephant weighing 40,000 N stands on one foot of area 0.1 m2. What
pressure is exerted on the ground?
Pressure = Force / Area
= 40,000 /0.1
= 400,000 N/m2
Example#2: What is the pressure exerted by a girl weighing 400 N standing on one 'stiletto'
heel of area of 0.00001 m2?
Pressure = force / area = 400 / 0.00001 = 40000000 N/m2
.This is a hundred times bigger than the elephant's pressure on ground.
Example#3: A woman having a weight of 50 N and wearing a pointed heel of 0.1 m2 would
apply a pressure of 500 N; whereas, a woman having the same weight, but wearing a heel of
0.5 m2 would apply a pressure of 100 N. So which lady can walk easily on sand?
The one with a larger area of heel because a smaller heel would apply more pressure and
would dip deeper in sand.
Work, energy and power
Work
1 Relate (without calculation) work done to the magnitude of a force and distance
moved in the direction of the force
Work is done whenever a force makes something move. The unit for work is the Joule (J).
The work done is always directly proportional to the magnitude of the force and the distance
moved in the direction of the force.
Page 94 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
2 Recall and use W = Fd = ΔE
Work done = force × distance moved in the direction of the force = change in energy
W = Fd = ΔE
(a) The diagram shows an energy flow for a motorbike. Fill in the gaps in the diagram.
(b) The motorbike travels 2.0 km. The driving force is 700 N. Calculate the work done
in joules by this driving force.
Work done = ........................................................... J
Solution:
a) i- Chemical Energy
ii- 30 000 J
iii- Heat+Sound
b) convert 2.0 km into metres as 2000 m. Using Work done = F x d = 700 x 2000 = 14 00
000 J
Energy
1 Demonstrate an understanding that work done= energy transferred
From the equation W = Fd = ΔE
;
work done = energy transferred (remember this)
When I push (pushing is applying a force) a table, it will move a certain distance, therefore,
work is done. Work done = Force x distance.
As the table is moved, the table gains Kinetic energy at the cost of my body‟s chemical
energy. Hence, whenever work is done, energy is transferred from one form to another.
2 Demonstrate understanding that an object may have energy due to its motion (kinetic
energy, K.E.) or its position (potential energy, P.E.) and that energy may be transferred
and stored
Kinetic energy is movement energy. When an object is moving fast it has more KE. KE can
be calculated by the following formula.
Kinetic energy = ½ mass x 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚𝟐
Page 95 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
When you ride a bicycle you convert your body‟s chemical energy to kinetic energy.
Similarly, an engine converts chemical energy in petrol to kinetic, heat and sound energy.
Potential Energy is stored energy. In fact, gravitational, chemical, strain or elastic and
nuclear energy are forms of potential energy.
Energy can be transferred from one form to another as shown above. It can also be stored e.g.
energy from the sun (light energy) can be used by photosynthetic plants to form
carbohydrates which possess stored chemical energy.
In summary, an object may have energy because of its movement (kinetic energy) or
because of its position, for example a book on a shelf has gravitational potential energy - it
can fall off the shelf. Energy can be transferred from one form to another for example if the
book falls off the shelf its GPE is turned into KE. Energy can be stored, for example, a book
on a shelf stores GPE and a glucose molecule stores chemical energy in its bonds. An object
can transfer its energy to another object, for example by conducting heat.
3 Give and identify examples of changes in kinetic, gravitational potential, chemical
potential, elastic potential (strain), thermal, sound and electrical potential energy that
have occurred as a result of an event or process
4 Recall and use the expressions K.E = ½ mv2 and gravitational potential energy,
G.P.E = mgh or change in G.P.E = mgΔh
Gravitational PE:
When you move an object above ground level, the object will store energy in it. This energy
is called Gravitational potential energy. This energy depends on how high the object is from
the ground. The higher it is above the ground, the more the energy stored. This energy can be
calculated from the following formula.
Gravitational Potential Energy (J) = Mass (kg) x Gravity (m/s2) x Height (m)
GPE = m x g x h
Extra information: Another way of looking at the GPE is that in order to raise an object above
ground level, we need to provide energy to it. This energy is called GPE, and is actually work
done against the gravitational force. This energy is released when the object falls back to
ground.
Elastic Potential Energy:
When you stretch a rubber band, it stores energy in it and returns that energy when it relaxes.
Similarly, when you stretch a spring or catapult, they store energy in them. This stored
energy is called Elastic Potential Energy or Strain Energy. Elastic Potential Energy or Strain
Energy is called stored energy because objects will always return back to their original
position and shape after using the energy. When you stretch a rubber cord or spring, your
Page 96 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
body‟s chemical energy is converted to kinetic energy to stretch the rubber or spring. Your
energy is then stored in the stretched object as elastic potential energy.
Chemical Potential Energy:
Energy stored by chemicals is called chemical energy. Examples are fossil fuels.
Thermal Energy:
When food is eaten it reacts with the oxygen we breathe into our lungs and is slowly „burnt‟.
As a result, chemical energy stored in food becomes heat energy to warm the body and
kinetic energy for muscular movement.
Sound energy:
A microphone changes sound energy into electrical energy; a loudspeaker does the reverse
Electrical energy:
A battery changes chemical energy to electrical energy. The electrical energy can be further
changed to kinetic energy by an electric motor. A generator can convert kinetic energy to
electrical energy.
Some Facts which you need to know:
1 –Energy cannot be created nor destroyed; it can only be changed from one form to another.
This is called the Law of Conservation of Energy
2 – No energy transfer is 100% efficient.
Page 97 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
5 Recognise that energy is transferred during events and processes, including examples
of transfer by forces (mechanical working), by electric currents (electrical working), by
heating and by waves
Mechanical working is the transfer of
kinetic and potential energy. When a crane
uses an electric motor to lift a heavy load,
energy is transferred to the load by the
crane. This is called mechanical working
because kinetic energy in the crane is being
converted to gravitational potential energy
in the load by a force causing movement.
Electrical working is the transfer of
electrical energy. The potential difference
across a circuit component is the work done
to drive a unit charge through the circuit
component.
Electricity can be used to transport energy. The circuit contains devices for transforming
energy. In a torch, energy is transferred electrically from the battery to the bulb, where it is
transformed into light and heat. Thermal (heat) energy spreads out from hot objects. Waves
also transfer energy.
6 Apply the principle of conservation of energy to simple examples
The principle of conservation of energy states that energy cannot be created or destroyed,
hence, when work is done, energy is changed from one form to another. The most everyday
example of this is when we move, our cells turn chemical energy (in glucose) into thermal
and kinetic energy.
Energy cannot be created or destroyed. The total amount of energy before and after any
process/work always stays constant. However, after any process, energy is transformed from
one form to another.
For example, when 100 J is supplied to a lamp, it transfers 75 J to light and 25 J to heat. This
means that the total energy before and after remains as 100 J. The only difference is that
before the process, 100 J was in electrical form and after the process 100 J was in light and
heat energy form.
Page 98 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Answers:
(a) moving
(b) Chemical
(c) Sound & Heat
Power
1 Relate (without calculation) power to work done and time taken, using appropriate
examples
Power (W) = Work done (J) / Time Taken (s)
[symbols of units are given in brackets]
2 Recall and use the equation P = ΔE / t in simple systems, including electrical circuits
P = ΔE / t
where P is power in watts; ΔE is change in energy in joules; t is time in seconds
Energy resources
1 Distinguish between renewable and nonrenewable sources of energy
 Renewable sources of energy: are inexhaustible, for example solar, hydroelectric,
wind etc.
 Non-renewable sources of energy: are exhaustible for example fossil fuels
Page 99 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
2 Describe how electricity or other useful forms of energy may be obtained from:
 chemical energy stored in fuel
 nuclear fission
 water, including the energy stored
 heat and light from the Sun (solar cells
in waves, in tides, and in water
and panels)
 wind energy
behind hydroelectric dams
 geothermal resources
Chemical energy: Fuels can be burnt in thermal power stations to transform the stored
chemical energy to thermal energy which makes steam to turns turbines (kinetic energy)
which then produce electricity. Advantage: cheap, plentiful, and low-tech. Disadvantage:
harmful wastes - produces greenhouse gases and pollutant gases.
Hydroelectricity from dams: river and rain water fill up a lake behind a dam. As water
rushes down through the dam, it turns turbines which turn generators.
Tidal power scheme: a dam is built across a river where it meets the sea. The lake behind the
dam fills when the tide comes in and empties when the tide goes out. The flow of water turns
the generator. Advantage: no greenhouse gases are produced. Disadvantage: expensive,
can‟t be built everywhere, and not as reliable because it depends on the height of the tide
which varies daily, monthly and seasonally. Can cause silt to build and can disrupt fish.
Wave energy: generators are driven by the up and down motion of the waves at sea.
Advantage: does not produce greenhouse gases. Disadvantage: difficult to build
Geothermal resources: water is pumped down to hot rocks deep underground and rises as
steam which can then be used to turn turbines. Advantage: no carbon dioxide is produced.
Disadvantage: deep drilling is difficult and expensive
Nuclear fission: uranium atoms are split by shooting neutrons at them. Advantage: produces
a lot of energy from using very little resources. Disadvantage: produces radioactive waste
Solar cells: are made of materials that can deliver an electrical current when they absorb light
energy
Solar panels: absorb the energy and use it to heat water. Advantage: does not produce
carbon dioxide. Disadvantage: variable amounts of sunshine in some countries.
Wind energy: giant windmills called wind turbines, with two or three blades, drive
electrical generators. „Wind farms‟ of 20 to 100 turbines provide enough electricity for
thousands of homes in the UK and provide a useful „top-up‟ to the National Grid.
Advantage: wind turbines provide a clean and renewable source of energy. Disadvantage:
wind turbines can be noisy and may be considered unsightly so there is some environmental
objection to wind farms, especially as the best sites for setting up turbines are often in coastal
or upland areas of great natural beauty.
Page 100 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
3 Give advantages and disadvantages of each method in terms of renewability, cost,
reliability, scale and environmental impact
Type of energy Renewable
or nonrenewable
Wind
Renewable
Form of
Energy
Conversion
Kinetic to
Electrical
Advantages
Disadvantages
1-renewable.
2-no CO2 pollution.
3-very cheap
electricity after few
years.
Water (HEP)
Renewable
GPE to
Electrical
Geothermal
Resource
Renewable
GPE to
Electrical
Solar Heating
Systems
Renewable
Light to
Electrical
Solar Cells
Renewable
Light to
Electrical
Fossil Fuels
(natural gas,
coal and
petroleum)
Nonrenewable
Chemical
to
Electrical
Nuclear Power
Nonrenewable
Nuclear
Potential
Energy to
Thermal +
Kinetic
1-renewable.
2- no CO2 pollution.
3- very cheap and
reliable electricity.
1-renewable.
2- no CO2 pollution.
3- low cost to run
4- reliable
1-renewable.
2- no CO2 pollution.
3-low maintenance
1-renewable.
2- no CO2 pollution.
3- easy to install
4- low maintenance
1- cheap, plentiful,
and low-tech.
2- reliable in that
they can produce
electricity at any
time of day and in
any season of the
year as long as fuel
is available.
1-renewable.
2- no CO2 pollution.
3- produces a lot of
energy from using
very little resources
4-reliable
1-expensive to install.
2-dangerous for birds.
3-requires large spaces of land.
4- not very reliable because the
output of a wind turbine changes
with the strength
of the wind
1- expensive to install.
2-dangerous for wildlife.
3-flooding risk and damage to
environment.
1- expensive to install
2-not available everywhere.
3- deep drilling is difficult and
expensive
1- expensive to install
2- If there is no Sun it won't work
1-expensive to install.
2- the output of a solar cell changes
with the intensity of light falling on
it
1- harmful wastes - produces
greenhouse gases and pollutant
gases.
2- oil spills can cause environmental
damage
3- natural gas can cause explosions
1-expensive to install, maintain and
decommission.
2-produces radioactive wastes.
4 Understand that the Sun is the source of energy for all our energy resources except
geothermal, nuclear and tidal
Apart from nuclear, geothermal, hydroelectric or tidal energy, the Sun is the source for all our
energy resources.
Page 101 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
5 Understand that the source of tidal energy is mainly the moon
The moon is the source of tidal energy. Its gravitational pull causes the level of the ocean‟s
surface to rise and fall. Water can be trapped behind a dam at high tides and released at lower
tides to drive turbines and generators.
6 Show an understanding that energy is released by nuclear fusion in the Sun
Energy is released in the Sun by the process of nuclear fusion. In nuclear fusion, two
hydrogen atoms collide and fuse (join up) to form an atom of helium. Nuclear fusion requires
very high temperatures and pressures, both of which can be found on the Sun.
Thermal Physics
Simple kinetic molecular model of matter
1 State the distinguishing properties of solids, liquids and gases
Solids: have a fixed shape and volume
Liquids: have a fixed volume but change shape depending on their container
Gases: do not have a fixed shape or volume. Gases fill up the space or volume of their
containers
2 Relate the properties of solids, liquids and gases to the forces and distances between
the molecules and to the motion of the molecules
Solids
Liquids
Gases
Attractive forces
acting between
particles
Very strong
Distances between
particles
Motion of particles
Very close to each
other
Weaker than solids
but stronger than in
gases
No forces acting
Slightly further apart
Particles can only
vibrate about fixed
positions
Particles can flow
Far apart
Move freely about
Page 102 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
3 Describe qualitatively the molecular structure of solids, liquids and gases in terms of
the arrangement, separation, and motion of the molecules
Solids
Liquids
Gases
Arrangement of
particles
Particles tightly
packed together.
Particles are closely
packed together but
not as tightly as in
solids.
Particles are spaced
far apart from each
other.
•Liquids and gases do not have a fixed
shape because of their weak forces of
attraction. Gases can be compressed
because there is plenty of space between
the particles; solids can‟t because such
Motion of particles
Particles can only
vibrate about fixed
positions
Particles can move
around, but they
remain close to each
other
Particles can move
far apart from each
other
space does not exist. The particles in a
solid cannot move because they are held
tightly together by the attractive forces, but
they can vibrate about fixed positions.
4 Describe qualitatively the pressure of a gas and the temperature of a gas, liquid or
solid in terms of the motion of its particles
The pressure of a gas is due to the gas particles colliding on the container walls. .
The pressure of a gas increases with temperature because the kinetic energy of the gas
particles increases, leading to more particles collisions with the walls of the container.
An increase in temperature of a gas, liquid or solid results in a corresponding increase in the
kinetic energy of the particles. However, solid particles only experience more vibration since
they are “locked” in fixed positions. Particles of liquids, on the other hand, experience both
vibrational and translational forms of kinetic energy.
In summary, heating solids, liquids, or gases, increases the kinetic energy of the particles.
5 Use and describe the use of thermometers to measure temperature on the Celsius scale
Liquids expand when they are heated because the particles gain more KE causing them to
become further apart and to take up a greater volume.
This concept is displayed when the liquid in thermometers expands and contracts when
temperature changes. The volume of the liquid taken up in the tube can be used to find the
temperature. Units of temperature on the thermometer are 0C (degrees celsius)
Page 103 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
6 State the meaning of melting point and boiling point, and recall the melting and
boiling points for water
•Melting point is the temperature at which a solid substance changes to liquid (it is
numerically equal to the freezing point).
•Boiling point is the temperature at which a liquid substance changes to gas. (it is numerically
equal to the condensation point).
Pure water melts at 0 0C and boils at 100 0C
7 Describe evaporation in terms of the escape of more-energetic molecules from the
surface of a liquid
Evaporation constantly occurs on the surface of liquids when the high energy particles escape
from the liquid, even at low temperatures. Boiling occurs only at the boiling point, and the
particles escape from everywhere in the liquid (not just on the surface).
Evaporation
Boiling
Slow process
Rapid process
Occurs only at the surface of Occurs throughout the liquid
the liquid
Occurs at all temperatures
Occurs at a fixed temperature known
as the boiling point of the liquid
8 Relate evaporation to the consequent cooling of the liquid
Evaporation causes cooling. Higher energy particles leave the surface of the liquid. If the
liquid is in contact with a body, energy is transferred from the body to these particles which
then evaporate leading to a drop in the body‟s temperature.
9 Demonstrate an understanding of how temperature, surface area and draught over a
surface influence evaporation
A few energetic molecules close to the surface of a liquid may escape and become gas
molecules. This process occurs at all temperatures and is called evaporation. It happens
more rapidly when
(i) the temperature is higher, since more molecules in the liquid are moving fast enough to
escape from the surface,
(ii) the surface area of the liquid is large, giving more molecules a chance to escape
because more are near the surface, and
Page 104 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
(iii) a wind or draught is blowing over the surface carrying vapour molecules away from the
surface, thus stopping them from returning to the liquid and making it easier for more liquid
molecules to break free.
Matter and thermal properties
1 Describe qualitatively the thermal expansion of solids, liquids and gases at constant
pressure
When matter is heated it expands and when cooled it contracts. Solids, liquids and gasses
expand when they are heated because the atoms vibrate more and this causes them to become
further apart, taking up a greater volume. Expansion is highest in gases, then liquids and
lowest in solids.
2 Identify and explain some of the everyday applications and consequences of thermal
expansion
1. Axles are shrunk by cooling in liquid nitrogen until
the gear wheels can be slipped on to them. On regaining
normal temperature, the axles expand to give a very tight
fit.
In the kitchen, a tight metal lid can be removed from a
glass jar by immersing the lid in hot water so that it
expands.
2. Bimetallic strips are strips made up of two metals which do not expand at the same rate.
They have multiple uses e.g.
a) Fire alarm: heat from the fire makes the bimetallic
strip bend and complete the electrical circuit, so
ringing the alarm bell
b) A thermostat in an iron
3. Thermal expansion is displayed when the liquid in thermometers expands leading to
temperature changes. The volume of the liquid taken up in the tube can be used to find out
the temperature.
4. Gaps have to be left on bridges to allow for expansion (rollers allow the bridge to expand)
Page 105 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Thermal processes
Conduction
1 Recognise and name typical good and bad thermal conductors
Conductors: Metals are the best electrical and thermal conductors because they have free
electrons (also known as delocalized electrons).
Insulators: Non-metals, liquids and gases are insulators. Materials such as wood, glass,
rubber, plastics and fabrics are insulators.
2 Describe experiments to demonstrate the properties of good and bad thermal
conductors
A simple demonstration of the different
conducting powers of various metals is
shown below. A match is fixed to one end
of each rod using a little melted wax. The
other ends of the rods are heated by a
burner. When the temperatures of the far
ends reach the melting point of wax, the
matches drop off. The match on copper
falls first, showing that it is the best
conductor, followed by aluminium, brass
and then iron.
Expt 2: the length of melted wax shows which material is the best conductor.
Expt 3: water at the top boils without the ice melting. This shows that water is a poor
conductor.
3 Explain conduction in solids in terms of molecular vibrations and transfer by
electrons
In non-metals, conduction happens when heat is supplied to the non metal, causing its atoms
to vibrate faster and pass on their vibrations to the adjacent atoms. In metals, conduction
Page 106 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
happens in the previous way and in another quicker way as follows; since electrons are free to
move, they travel randomly in the metal and collide with atoms, hence, passing on their
vibrations.
Convection
1 Recognise convection as the main method of energy transfer in fluids
Thermal energy (heat) travels through fluids such as liquids and gases mainly by convection.
2 Relate convection in fluids to density changes
3 Interpret and describe experiments designed to illustrate convection in liquids and
gases (fluids)
1, 2, 3 and 4 show
convection currents.
Streams of warm moving
fluids are called
convection currents. They
arise when a fluid is
heated because it expands,
becomes less dense and is
forced upwards by
surrounding cooler, denser
fluid which moves in under
it.
Convection can be shown in
water by dropping a few
crystals of potassium
permanganate down a tube
to the bottom of a beaker.
When the tube is removed
and the beaker heated just
below the crystals by a small
flame, purple streaks of
water rise upwards and fan
outwards.
A laboratory demonstration of convection
currents in air can be given using the
apparatus on the left. The direction of the
convection currents created by the candle is
made visible by the smoke from the touch
paper.
Black marks often appear on the ceiling
above a lamp or a radiator. They are caused
by dust being carried upwards in air
convection currents produced by the hot
lamp or radiator.
Radiation
1 Recognise radiation as the method of energy transfer that does not require a medium
to travel through
Page 107 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Whereas conduction and convection both need matter, radiation can occur in a vacuum;
particles of matter are not involved. Thus, radiation does not require a medium to travel
through. Radiation is the way in which heat from the Sun reaches us.
2 Identify infra-red radiation as the part of the electromagnetic spectrum often involved
in energy transfer by radiation
Infra-red radiation is part of the electromagnetic spectrum involved in energy transfer by
radiation. Radiation is the flow of heat from one place to another by means of
electromagnetic waves.
3 Describe the effect of surface colour (black or white) and texture (dull or shiny) on the
emission, absorption and reflection of radiation
Dull black surfaces are better absorbers of radiation than white shiny surfaces.
White shiny surfaces are better reflectors of radiation than dull black surfaces.
If you hold the backs of your hands on either side of
a hot copper sheet that has one side polished and the
other side blackened, it will be found that the dull
black surface is a better emitter of radiation than
the shiny one.
In general, surfaces that are good absorbers of
radiation are good emitters when hot.
4 Interpret and describe experiments to investigate the properties of good and bad
emitters and good and bad absorbers of infra-red radiation
Expt 1
Expt 2
Page 108 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Expt 1: boiling water in a metal cube heats all surfaces equally. The thermal radiation
detector is placed in turn at the same distance from each surface and the meter readings
compared.
Expt 2: the metal plates are placed at the same distance from a radiant heater and the
temperature readings from the thermometers are compared.
Conclusion:
 Matt black surfaces are the best emitters and absorbers of thermal radiation.
 Silver surfaces are the worst emitters and absorbers of thermal radiation.
Consequences of energy transfer
1 Identify and explain some of the everyday applications and consequences of
conduction, convection and radiation
Applications
 Solar panel: the sun‟s thermal radiation is absorbed by a matt black surface and
warms up the pipes containing water.
 Refrigerator: the freezer compartment is located at the top of the refrigerator. It cools
down the air which then sinks. Any warm air present rises to the top where it is
cooled. This creates a convection current which maintains a cold temperature.
 Metals are used in cooking pans because they conduct the heat well.
 A vacuum flask keeps hot liquids hot or cold liquids cold. Transfer by conduction and
convection is minimized by making the flask a double-walled glass with a vacuum inbetween the walls. Radiation is reduced by silvering both walls on the vacuum side.
 Houses in hot areas are painted white; the back of a refrigerator is painted black so
that the refrigerator loses heat more quickly; saucepans are polished/shiny to make
them poor emitters so that they keep their heat longer.
Consequences
 A metal spoon in a hot drink will warm up because it conducts heat.
 Convection currents create sea breezes. During the day the land is warmer and acts as
a heat source. During the night the sea acts as the heat source.
 A black saucepan cools better than a white one, and white houses stay cooler than
dark ones.
Page 109 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Properties of waves, including light and sound
General wave properties
1 Demonstrate understanding that waves transfer energy without transferring matter
The motion of ropes and springs and experiments by ripple tanks show that waves transport
energy from one place to another without transferring matter.
2 Describe what is meant by wave motion as illustrated by vibration in ropes and springs
and by experiments using water waves
3 State the meaning of speed, frequency, wavelength and amplitude
Wave speed (v) is the distance moved in the direction of travel of the wave by a crest or any
point on the wave in 1 second. (units are ms -1)
Frequency (f) is the number of waves passing any point per second.(units are Hertz; Hz). If
the end of a rope is moved up and down twice in a second, two waves are produced in this
time. The frequency of the wave is 2 vibrations per second or 2 hertz
Wavelength (λ) is the distance between two consecutive points on a wave in phase (i.e from
peak to peak) e.g. from crest to crest or compression to compression (units are metres; m).
Amplitude (a) is the height of a crest or the depth of a trough measured from the undisturbed
position of what is carrying the wave, such as a rope.
Period is the time taken for one oscillation in seconds.
Continuous ripples are studied more easily if
they are apparently stopped (‘frozen’) by
viewing them through a stroboscope.
Page 110 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
4 Distinguish between transverse and longitudinal waves and give suitable examples
Transverse waves have oscillations at right-angles to the direction of travel.
Longitudinal waves have oscillations in the direction of travel.
Transverse waves have crests (peaks) and troughs; whereas longitudinal waves (e.g. sound
waves) have compressions and rarefactions.
For transverse waves, the oscillations are
perpendicular to the direction of travel e.g.
light, water and seismic S- waves. A
transverse wave can be sent along a rope (or a
spring) by fixing one end and moving the
other rapidly up and down.
For longitudinal waves, the oscillations are in
the direction of travel e.g sound and Seismic
P- waves from earthquakes.
The Cs and Rs below show compressions and
rarefactions on the spring.
A sound wave, produced for example by a
loudspeaker, consists of a train of
compressions („squashes‟) and rarefactions
(„stretches‟) in the air
5 Describe how waves can undergo:
 reflection at a plane surface
 refraction due to a change of speed
Reflection at plane surface
Water cannot pass through surfaces so it bounces back.
It bounces back with the same speed, frequency and wavelength.
The angle of incidence (i) = the angle of reflection (r)
Page 111 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Refraction due to a change of speed
Refraction: when the water waves pass through shallower water they slow down. When
waves slow down they change direction.
Things to note about refraction:
 waves slow down when they pass from a less to a more dense material and vice versa
 when a wave is slowed down, it is refracted towards the normal (i > r)
 when a wave is sped up, it is refracted away from the normal (i < r)
 deep water is denser than shallow water
 angle of incidence ≠ angle of reflection.
6 Recall and use the equation v = f λ
Wave speed = frequency × wavelength
v=f×λ
Question: Calculate the frequency of a wave having wavelength = 1 x 10 -7 m and speed = 3 x
105 km/s.
Solution: Apply v = f x λ formula and then plug in the values and calculate. But first
convert km/s into m/s. Therefore, v would become 3 x 108 m/s
Hence,3 x 108 = f x 1 x 10-7 m
so, f = 3 x 1015 Hz
Page 112 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
7 Understand that refraction is caused by a change in speed as a wave moves from one
medium to another
As demonstrated above, refraction is caused by a change in speed as a wave moves from one
medium to another
Light
Reflection of light
1 Describe the formation of an optical image by a plane mirror and give its
characteristics
Rays from an object reflect off the mirror into our eyes.
The image has these properties:
 the image is the same size as the object
 the image is the same distance from the mirror as
the object
 a line joining equivalent points of the image and
object meets the mirror at a right angle
 the image is virtual: no rays actually pass through
the image and the image cannot be formed on a
screen
 the image is laterally inverted
• Laws of reflection:
Angle of incidence = angle of reflection
The incident ray, reflected ray and normal are always on
the same plane (side of mirror)
Looking at the diagram
on the left, the image in
the mirror is laterally
inverted.
2 Recall and use the law angle of incidence i = angle of reflection r recognising these
angles are measured to the normal
[Objective covered above]
Page 113 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
3 Perform simple constructions, measurements and calculations for reflection by plane
mirrors
[To be done practically]
Refraction of light
1 Interpret and describe an experimental demonstration of the refraction of light
 As the ray of light enters the block, it slows
down and bends towards the normal
 As the ray of light exits the block, it speeds up
and bends away from normal
 Angle of incidence ≠ angle of refraction
 Frequency does not change, only speed and
wavelength
Thin converging lens
1 Describe the action of a thin converging lens on a beam of light
A beam of light is composed of light
rays. When parallel rays of light pass
through a convex (converging) lens,
they are focused to a point called the
principal focus. Since light can fall
on both faces of a lens, we have two
focal points, one on each side. The
convex lens is represented as a thin
line in ray diagrams.
2 Use the terms principal focus and focal length
F is the principal focus
Distance between C and F (f) is the focal length
Page 114 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
3 Draw ray diagrams for the formation of a real image by a single lens
Step 1: Draw the lens with a horizontal axis passing through the middle of it.
Step 2: Mark the positions of the principal focuses F on either side, at equal distances from
the lens. Mark the position of the object O, an arrow standing on the axis.
Step 3: Draw ray 1, a straight line from the top of the arrow and passing undeflected through
the middle of the lens.
Step 4: Draw ray 2, from the top of the arrow parallel to the axis. As it passes through the
lens, it is deflected down through the principal focus. Look for the point where the two rays
cross. This is the position of the top of the image I.
Examples of ray diagrams
 Object (O) beyond 2F
 Used in camera
Page 115 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
 Object (O) between F and 2F
 Used in projector
Object (O) at 2F
4 Use and describe the use of a single lens as a magnifying glass
The previous diagrams gave us real images; however, if the object is between the lens and
F, a virtual image is created, instead of a real image. This allows a single convex lens to be
used as a magnifying glass. The image is behind the object, virtual, erect (i.e. not inverted),
and larger than the object.
Page 116 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Electromagnetic spectrum
1 Describe the main features of the electromagnetic spectrum in order of frequency,
from radio waves to gamma radiation (γ)
2 State that all electromagnetic waves travel with the same high speed in a vacuum and
approximately the same in air
All electromagnetic waves travel with the same high speed in a vacuum and approximately
the same in air.
3 State that the speed of electromagnetic waves in a vacuum is 3.0 × 10 8 ms-1
All electromagnetic waves:
 travel at the speed of light: 3 × 108 ms-1 in a vacuum
 do not need a medium to travel through i.e. they can travel through a vacuum
 can transfer energy
 are produced by particles oscillating or losing energy in some way
 are transverse waves
4 Describe typical properties and uses of radiations in all the different regions of the
electromagnetic spectrum including:
 radio and television communications (radio waves)
 satellite television and telephones (microwaves)
 electrical appliances, remote controllers for televisions and intruder alarms
(infra-red)
 medicine and security (X-rays)
Uses:
Radio waves are used in radio and television communications.
Microwaves are used in satellite television and telephones because they easily pass through
the Earth‟s atmosphere as they travel up to a broadcasting satellite in space, after which they
are sent back down to subscribers on Earth.
Infrared is used in electrical appliances (radiant heaters and grills), intruder alarms and
remote controllers for televisions.
Page 117 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Monochromatic light is light, of a single wavelength and colour. It is used in lasers.
Ultra violet light causes fluorescence. It is used to sterilize equipment.
X-rays are used in medicine (x-ray photography and killing cancer cells) and security. X-rays
can penetrate solid materials hence their use in security scanners at airports. In medicine,
bones absorb X-rays more strongly than flesh, so bones appear as a shadow in the image
formed by X-ray photography. In medicine, X-rays can also be used to kill cancer cells.
Gamma rays are used to sterilize food and equipment. They are also used in radiotherapy to
destroy cancer cells.
5 Demonstrate an understanding of safety issues regarding the use of microwaves and
X-rays
Safety issues:
 X-rays cause cancer due to cell mutations
 Microwaves can heat and destroy living cells
6 State the dangers of ultraviolet radiation, from the Sun or from tanning lamps
UV radiation can cause skin cancer and damage retina
Sound
1 Describe the production of sound by vibrating sources
Sound is a form of energy that is produced by vibrations. It travels as waves. A Sound wave
can only be produced in matter/medium (i.e it is a mechanical wave) and hence, cannot travel
through a vacuum.
All vibrating sources produce sound. Sources of sound all have some part that vibrates. A
guitar has strings, a drum has a stretched skin and the human voice has vocal cords.
2 Describe the longitudinal nature of sound waves
Sound waves are longitudinal in nature i.e. particles move parallel to the direction of wave
travel.
Page 118 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
3 Describe the transmission of sound waves in air in terms of compressions and
rarefactions
Sound waves come from a vibrating source for example a loudspeaker. As the loudspeaker
cone vibrates, it moves forwards and backwards, which squashes and stretches the air in
front. As a result, sound waves are transmitted as a series of compressions (squashes) and
rarefactions (stretches) that travel out through the air.
It should be noted that
the air molecules are
merely pushed back and
forth causing vibrations
which travel to our ears.
The individual air
molecules do not travel
from the loudspeaker to
our ears.
4 State that the approximate range of audible frequencies for a healthy human ear is 20
Hz to20 000 Hz
Humans can hear frequencies between 20Hz and 20 000Hz. An alarm has alternating high
and low pitched sounds. Both should fall within the audible frequency range in order to be
detected by humans.
5 Show an understanding that a medium is needed to transmit sound waves
Sound cannot travel through a vacuum because there are no molecules or particles in a
vacuum to vibrate back and forth. A medium eg. air is required for the transmission of sound.
6 Describe and interpret an experiment to determine the speed of sound in air,
including calculation
Question: A man shouts close to a high wall. He hears one echo. If the man is 40 m from the
wall, how long after the shout will the echo be heard? (Speed of sound in air = 330 m/s.)
Step 1: Calculate the distance travelled by the sound. Note that this is twice the distance from
the man to the wall (since the sound travels there and back).
Distance travelled by sound = 2 × 40 m = 80 m
Step 2: Calculate the time taken for the sound to travel this distance.
Time taken =
𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒
𝑠𝑝𝑒𝑒𝑑
=
80𝑚
330𝑚 /𝑠
= 0.24s
So the man hears
the echo 0.24 s after
his shout.
Page 119 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
The diagram shows a „time-offlight‟ method for measuring the
speed of sound. The wooden
blocks and the two microphones
are arranged in a straight line. The
bang from the blocks is picked up
first by microphone 1, setting off a
timer which stops when the bang is
picked up by microphone 2. The
speed of sound is calculated using
the distance between the two
microphones and the time taken by
the sound to travel between them.
The formula speed =
used
𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒
𝑡𝑖𝑚𝑒
is
7 Recognise that sound travels faster in liquids than gases and faster in solids than in
liquids
Sound travels fastest in solids followed by liquids and then lastly in gases.
8 Relate the loudness and pitch of sound waves to amplitude and frequency
 Higher frequency → a higher pitch
 Larger amplitude → louder sound
9 Describe how the reflection of sound may produce an echo
An echo is produced when sound travels from the source and bounces off hard surfaces or
walls such that it is reflected back to the source. The more the reflecting surfaces, the more
the echoes heard.
Electrical quantities
Electric charge
1 State that there are positive and negative charges
There are 2 types of charges: namely positive and negative charges.
2 State that unlike charges attract and that like charges repel
Unlike charges attract and like charges repel.
Page 120 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
3 Describe and interpret simple experiments to show the production and detection of
electrostatic charges by friction
The production of charges by friction (rubbing) can be explained by supposing that
electrons are transferred from one material to the other. For example, when a polythene rod
is rubbed with a silk cloth, electrons go from the silk cloth to the polythene rod, leaving the
silk cloth positively charged. The polythene rod now has more electrons than protons and
becomes negatively charged. Note that it is only electrons which move; the protons remain
fixed in the nuclei.
4 State that charging a body involves the addition or removal of electrons
Charging a body involves the addition or removal of electrons
5 Distinguish between electrical conductors and insulators and give typical examples
 Conductors are materials that have free or mobile electrons that travel through them
e.g metals (copper, gold, silver etc). Metals are the best electrical conductors because
they have free electrons which move from one place to another. These electrons also
make them good thermal conductors.
 Insulators are materials that do not have free or mobile electrons; hence, they do not
conduct at all e.g. wood, rubber, air, plastic. Their electrons are firmly held to atoms,
meaning they do not move, but they can be transferred by rubbing (as shown above).
Current, potential difference and electromotive force (e.m.f.)
1 Demonstrate understanding of current, potential difference, e.m.f. and resistance.
2 State that current is related to the flow of charge
Current is the rate of flow of charge through a conductor. Its SI unit is the Ampere (A).
Page 121 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Potential difference, or PD for short, is also known as voltage. Potential difference is the
amount of energy the cell gives the electrons it pushes out. It is measured in volts (V) and is
measured by a voltmeter (connected in parallel).
The electromotive force (e.m.f): When no current is drawn from a battery it is said to be an
„open circuit‟ and its terminal p.d. is a maximum. This maximum voltage is termed the
electromotive force (e.m.f.) of the battery. Like potential difference, e.m.f. is measured in
volts. The p.d. at the terminals of a battery decreases slightly when current is drawn from it.
This effect is due to the internal resistance of the battery which transfers some electrical
energy to heat as current flows through it.
Resistance: The opposition that a conductor offers to the flow of current is called its
resistance. A good conductor has a low resistance and a poor conductor has a high
resistance.
3 Know and use the formula Q = It
Charge (Q) = current (A) x time (s)
Q=Ixt
units are Q in coulombs (C)
I in amps (A)
t in seconds (s)
4 Show understanding that a current is a rate of flow of charge and recall and use the
equation I = Q / t
Current is the rate of flow of charge through a conductor. The SI unit is the Ampere (A).
I=Q/t
5 State that current in metals is due to a flow of electrons
Current in metals is due to a flow of electrons.
6 State that the potential difference (p.d.) across a circuit component is measured in
volts
The potential difference (p.d.) across a circuit component is measured in volts
7 Use and describe the use of an ammeter and a voltmeter, both analogue and digital
An ammeter measures the current in a circuit. It is
connected in series. It can be digital or analogue.
Current is measured in Amperes (A)
A voltmeter measures the voltage in a circuit. It is
connected in parallel. It can be digital or analogue.
Voltage is measured in volts (V).
Page 122 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
8 State that the electromotive force (e.m.f) of an electrical source of energy is measured
in volts
e.m.f. is measured in volts.
Resistance
1 State that resistance = p.d. / current and understand qualitatively how changes in p.d.
or resistance affect current
2 Recall and use the equation R = V / I
Resistance (Ω) = potential difference (V) / current (A)
R=V/I
@ constant p.d;
increase in resistance leads to a decrease in current
@ constant resistance;
increase in p.d leads to an increase in current
3 Recall and use quantitatively the proportionality between resistance and length, and
the inverse proportionality between resistance and cross-sectional area of a wire
R=ρ
𝐿
𝐴
R is resistance; ρ resistivity; L is length; and A is cross sectional area
Factors affecting resistance:
The resistance of a wire
(i)
(ii)
(iii)
increases as its length increases,
increases as its cross-sectional area decreases,
depends on the material.
Page 123 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Electric circuits
Circuit diagrams
1 Draw and interpret circuit diagrams containing sources, switches, resistors (fixed and
variable), lamps, ammeters, voltmeters and fuses (Symbols for other common circuit
components will be provided in questions)
Symbols for common circuit components:
Notice the two symbols for a lamp. The
diagram on the right represents a circuit
diagram which shows a battery (source); 3
resistors; 2 ammeters; and 1 voltmeter. V1 is
measuring p.d across R1 hence it‟s connected in
parallel. A1 measures current from the source
hence it‟s connected in series. A2 measures
current through the 6 ohm resistor.
Series and parallel circuits
1 Understand that the current at every point in a series circuit is the same
2 Calculate the combined resistance of two or more resistors in series
3 Recall and use the fact that the sum of the p.ds across the components in a series
circuit is equal to the total p.d across the supply
Page 124 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Current at every point in a series circuit is the
same. Hence, I = I1 = I2
I
The potential difference across each resistor is
different based on their resistance. The sum of
the potential differences across the resistors
gives the total pd of the cell. V = V1 + V2.
Combined resistance: RTotal = R1 + R2
4 State that, for a parallel circuit, the current from the source is larger than the current
in each branch
The current splits at each branch in a parallel circuit so the total current from the source is
always greater than the current in one branch
5 Recall and use the fact that the current from the source is the sum of the currents in
the separate branches of a parallel circuit
The current from the source is the sum of the currents in the separate branches of a parallel
circuit
6 State that the combined resistance of two resistors in parallel is less than that of either
resistor by itself
The combined resistance of two resistors in parallel is less than that of either resistor by itself
7 Calculate the combined resistance of two resistors in parallel
Current: I = I1 + I2
V = V1 = V2
1
𝑅 𝑇𝑜𝑡𝑎𝑙
=
1
𝑅1
+
1
𝑅2
Page 125 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Total resistance across QW is calculated as
follows
1
𝑅 𝑇𝑜𝑡𝑎𝑙
=
1
4.0
+
Hence; Rtotal =
1
6.0
12
5
=
3+2
12
=
5
12
= 2.4 Ω
 If R1 = 3.0 Ω; then total resistance of the circuit = 3.0 + 2.4 Ω = 5.4 Ω
 Since V = IR;
I = V/R = 12.0/ 5.4= 2.22A to 2 decimal places.
8 State the advantages of connecting lamps in parallel in a circuit
1. Lights are connected in parallel to avoid them from becoming dim because in parallel
connections, each lamp receives the same voltage (which is equal to the mains supply
voltage). Voltages below the mains supply will make the lamps dim.
2. In parallel connections, unlike in series connections, if one bulb fails, the others
remain lit.
3. It is easier for current to flow in parallel connections as compared to series
connections because the effective resistance is less.
Electrical Energy
1 Recall and use the equations P = IV and E = IVt
Electrical power (W) = Current (A) × Voltage (V)
P=I×V
Electrical energy (J) = power (W) × time (s)
E = P × t (Since P = I × V)
Electrical energy (J) = Voltage (V) × Current (A) × time (s)
E=I×V×t
Dangers of electricity
1 Identify electrical hazards including:
 damaged
insulation
 overheating of
cables
 damp conditions
•Damaged insulation: when the insulation is damaged, there is risk of contact with the live
wire leading to electric shock which can cause serious injury.
•Overheating of cables: when too much current flows e.g. because of a short circuit, it may
cause a fire because the cables get too hot.
•Damp conditions: water can conduct a current, so if electrical equipment is wet someone
might get electrocuted.
Page 126 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
2 State that a fuse protects a circuit
The purpose of a fuse is to protect a circuit.
3 Explain the use of fuses and choose appropriate fuse ratings
A Fuse is a thin piece of wire which overheats and
melts (we say the fuse „blows‟) if the current is too
high. A fuse prevents overheating and risk of
catching fire. A fuse will have a specific current
value or rating (e.g. 13A) so when choosing a
suitable fuse you must use the one which can have
the lowest current value but over the current value
of the appliance. Always replace with one of the
same value as recommended by the manufacturer
of the appliance.
Note that the current flowing
through resistors rated 5 Ω,
10 Ω and 25 Ω, adds up to
1.7A
Total current
1.7A = 1A + 0.5A + 0.2A
For (b); effective resistance for parallel connections is less than that of series connections.
For parallel connection,
1
𝑡𝑜𝑡𝑎𝑙 𝑟𝑒𝑠𝑖𝑠𝑡𝑎𝑛𝑐𝑒
=
1
5
+
1
10
+
1
20
=
4+2+1
20
=
7
20
total resistance =
20
7
= 2.86 Ω
For series connection, total resistance = 5 + 10 + 25 = 40 Ω
Page 127 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.
Physics section
Diagram “a” shows an electric circuit set up in a lab, and diagram “b” shows the circuit
diagram of that very same electric circuit.
Page 128 of 128
This file was downloaded from StudyLast.com. It is not allowed to publish it elsewhere. Only the buyer can use this file.