Different types of rocks
1. Igneous Rocks
 Formed when magma (molten rock beneath the Earth’s crust) cools and solidifies.
 A mixture of different minerals
 Large crystals can be formed
(Examples: Obsidian, Granite, Basalt)
2. Sedimentary rocks
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Formed by the accumulation of sediments (little fragments of rocks). The weight of new sediments presses on older sediments, forming
solid rocks
Fossils can be formed
Made of grains/particles
Porous
Has layers
(Examples: Sandstone, Limestone, Shale)
3. Metamorphic rocks
 Formed by high temperatures and pressures underground
 Hard
 No gaps
 Not porous
(Examples: Marble, Quartzite, Slate)
Models of the Universe
Geocentric Model: A model of the solar system/universe where Earth is at the centre
Scientists who supported the model:
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Plato (400 BCE)
Aristotle (400 BCE)
Ptolemy (100 CE)
Heliocentric model: A model of the solar system/universe where the Sun is at the centre
Scientists who supported the model:
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Aristarchus (300 BCE)
Copernicus (1542 CE)
Kepler (1609 CE)
Galileo (1610 CE)
Discoveries of the planets and moons
Known since ancient times (Visible with the naked eye)
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5.
6.
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Mercury
Venus
Mars
Jupiter
Saturn
The Moon
The Sun
Uranus
Discovered by Sir William Hershel in 1781.
Neptune
Discovered by Johann Gottfried Galle, Urbain Jean Joseph Le Verrier, John Couch Adams in 1846.
Pluto
Discovered by Clyde Tombaugh in 1930.
The Galilean moons of Jupiter
Moons of Jupiter discovered by Galileo Galilei in 1610
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2.
3.
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Io
Europa
Ganymede
Callisto
The rings of Saturn
Discovered by Galileo Galilei in 1610.
Mountains and Craters on the Moon
Discovered by Galileo Galilei in 1610.
Order of the Solar System
Position (Closest to furthest from the Sun)
Sun, Mercury, Venus, Earth, Mars, (Asteroid belt), Jupiter, Saturn, Uranus, Neptune, Pluto
Size (Biggest to smallest)
Sun, Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, Mercury
Temperature (Hottest to coldest)
Sun, Venus, Mercury, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto
Brightness (Brightest to darkest from Earth)
Sun, Venus, Jupiter, Mars, Mercury, Saturn, Uranus, Neptune, Pluto
Keys
Keys are used to identify different species. A key is a set of questions about the organism you want to identify.
Examples:
Proton and Electron number
Atomic number
The number of protons in an atom
Mass number
The number of protons and neutrons in an atom
Number of particles in an atom
Protons = Mass – Neutrons
Electrons = Protons
Neutrons = Mass – Protons
Electronic Structure
Electrons are arranged in shells or orbitals around the nucleus of an atom
Maximum number of electrons in each shell/orbital:
2,8,8
Structure of an Atom
Approximated mass of subatomic particles
Proton = 1
Neutron = 1
Electron = 0
Charge of subatomic particles
Proton (+)
Neutron (0)
Electron (-)
Sounds
Loudness = Amplitude
Pitch = Frequency
Examples:
Higher frequency = Shorter wavelength = Higher pitch
Lower frequency = Bigger wavelength = Lower pitch
Higher amplitude = Higher Loudness
Lower amplitude = Lower Loudness
Pollination and Fertilisation in Plants
Pollination: The act of transferring pollen grains from the male anther of a flower to the female stigma
Fertilisation: When a sperm cell fuses with an egg inside an ovule. This process develops a seed.
Structure of a flower
Parts of a female flower (Pistil)
1. Stigma
 Receives pollen
 Starts the fertilization process
2. Style
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Long, slender stalk
Connects the stigma to the ovary
3. Ovule
 Forms seeds
 In the ovary
Parts of a male flower (Stamen)
1. Anther
 Produces pollen
 Stores pollen
2. Filament
 Supports the anther
Other parts of a flower
1. Petals
 Most colour part of a flower
 Attracts animals (pollinators)
2. Sepal
 Encloses and protects developing reproductive structures
 Green and leaf-like
Common Pollinators
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Bees
Wasps
Moths
Butterflies
Flies
Beetles
Birds
Seed Formation
1. Male and female nucleus fuses, producing a zygote
2. Zygote divides, forming an embryo
3. Ovule begins to change, forming into a seed
*Fruits are the ovaries of plants
Example:
Structure of a seed
3 main components of a seed
1. Embryo
 Developed from fertilized egg
 Most important part of a seed
2. Endosperm/ Perisperm
 Contains nutrients
 Provides nutrients
 Supports the embryo during germination (sprouting of a seed)
3. Seed-coat
 Two layers: Testa (thick), Tegmen (thin)
 Protects the seed from sunlight & water
 Prevents loss of water and parasites
Elements, compounds, and mixtures
Elements
The simplest substances that cannot be broken down into simpler formats
Examples.: Oxygen (O), Iron (Fe), Carbon (C)
Compounds
The substances that contain atoms of two or more different elements and are chemically joined together
Examples: Water (H20), Carbon Dioxide (CO2), Iron Oxide (Fe2O3)
Mixtures
Made when two or more substances are combined physically, but not chemically
Examples: Air, Seawater, Mud
*The components of a mixture can be easily separated
Molecules
Substances containing 2 or more atoms that are chemically joined together
Examples: Oxygen air (O2), Water (H20), Nitrogen air (N2)
Solutions
A mixture containing a solvent and a solute
Example: (Salt water: Salt is the solute; water is the solvent)
Common methods for separation of mixtures
1. Chromatography
 Separating colours from a mixture
2. Distillation
 Separating mixtures comprised of two or more pure liquids.
 Liquids are vaporized, condensed, and isolated
3. Evaporation
 Separating mixtures with one or more dissolved solids
 Drives off liquid components from solid components
4. Filtration
 Separating out pure substances in mixtures comprised of particles through a filter
Electricity, Circuits and Brightness of Bulbs
Static Electricity
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Results of imbalances between negative and positive charges in an object
The transfers of electrons between objects
Examples: Lightning, Balloon and hair, Doorknobs and hands
*Like charges repel, opposite charges attract
*Coulombmeters can be used to find out if an object has positive or negative charge
Conductors
Materials that allow electricity to pass through them
Examples: Copper, Iron, Mercury
Insulators
Materials that don’t allow electricity to pass through them
Examples: Plastic, Rubber, Wood
Electric Current
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Flow of electric charge
Creates magnetic fields (Electromagnet)
Measured in Amperes (Amp, A)
Measured using ammeter
Voltage
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The “pressure” from an electrical power source that pushes electrons through a conducting loop
Measured in volts (V)
Measured using voltmeter
Higher voltage = Higher current
Circuit types
Parallel Circuit
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Comprises of branches
Current divides
Voltage is the same throughout circuit
Current may vary throughout circuit
Bulbs are usually brighter than in series circuits
Series Circuit
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Current flows through each component
Same current flows throughout circuit
Bulbs are usually dimmer than in parallel circuits
*Electrons flow from negative to positive
*Current flows from positive to negative (opposite direction of electron flow)
Digestive system
Digestion: The breakdown of large molecules into small molecules so they can be absorbed
Absorption: Movement of digested food molecules through the wall of the intestine, into the blood or lymph
The digestive system is made up of the alimentary canal
The alimentary canal:
1. Mouth
 Teeth chew food into smaller pieces
 Saliva breaks down starch to sugar
2. Oesophagus
 Food passes through
3. Liver
 Makes bile (helps with fat digestion)
 Bile flows into small intestine
4. Stomach
 Contain hydrochloric acid that kills micro-organism in food
 Stomach juices break down protein to amino acids
5. Gall bladder
 Stores bile
6. Pancreas
 Produces pancreatic juice (helps with protein, starch, and fat digestion)
 Pancreatic juice flows into small intestine
7. Small Intestine
 Breaks down starch, protein, and fat into smaller molecules
 Starch, protein, fat, water, vitamins, and minerals are absorbed
 Absorption happens through the walls of the small intestine
8. Large Intestine
 Undigested food pass through here
 Absorbs water
 Faeces is formed
Teeth
 Hardest substances in the human body
 In the mouth
 Chews food into smaller pieces
Types of teeth
1. Incisors
 Chisel shaped
 Sharp edges
 Used for bite off food
2. Canines
 More pointed than incisors
 Used the same way as incisors
3. Premolars
 Broad surfaces with ridges
 Used for crushing and grinding food
4. Molars
 Similar to premolars, but bigger
 Used for crushing and grinding food
Structure of a tooth
Crown
1. Enamel : A very hard covering, containing calcium
2. Dentine : A layer containing liver cells
3. Pulp Cavity : Containing blood vessels and nerves
4. Gum
Root
5. Fibres : Help to hold tooth in jawbone
6. Jawbone
7. Blood supply : Supply blood
Nutrients
Protein
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Makes new cells
Makes enzymes
Makes antibodies
Supply energy
Carbohydrate
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Provide energy
Examples: Starch, Sugar
Fat
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Provides energy
Stored in the body
Provides insulation
Make new cell membranes
Vitamins and minerals
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Don’t provide energy
Found in fruits and vegetables
Fibre and water
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Keep food moving easily through the digestive system
Found in fruits, vegetables, whole seeds
70% of our body is made up of water
Diet
Enzymes
 Biological catalysts (substances that speed up a chemical reaction, but is not changed itself)
 Helps break down large molecules into smaller ones
Different types of animals
Vertebrates
Vertebrates are animals with backbones. They are classified into five groups called classes
1. Fish
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With fins
Covered with scales
Breathe using gills
Lay eggs in water
(Examples: Sardines, Salmon, Cod)
2. Amphibians
 Adults live on land, breathe using lungs
 4 limbs
 Have smooth skin without scales
 Lay eggs in water
 The young are called tadpoles
 Tadpoles develop in water, breathe using gills
(Examples: Frogs, Geckos, Toads)
3. Reptiles
 With scaly skins
 4 legs (except for snakes)
 Some live on land, some in water
 Lay eggs on land
(Examples: Snakes, Crocodiles, Dinosaurs)
4. Birds
 With wings, feather, and a beak
 Lay eggs on land
(Examples: Eagles, Cockatiels, Chickens)
5. Mammals
 With hair
 Give birth to young
 Young are fed on milk from the mother
(Examples: Humans, Chimpanzees, Wolves)
Invertebrates
invertebrates are animals without backbones. There are many different groups of
invertebrates. Only a few are listed below.
1. Molluscs
 With a soft body
 Muscular foot to move around
 Some have shells
(Examples: Slugs, Snails, Octopuses)
2. Annelids
 Worms with bodies
 Divided up into rings (segments)
 Don’t have legs
 Have tiny bristles called chaetae
(Examples: Earthworms, Leech, Polychaete)
3. Arthropods
 With jointed legs
 Divided into segments
 Have a skeleton on the outside (Exoskeleton)
 Most common kinds of animals on Earth
Several groups of arthropods are listed below:
1. Insects
 With 6 jointed legs
 Body divided into: Head, Thorax, Abdomen
 Most have 2 pairs of wings attached to thorax
 Legs are attached to thorax
 1 pair of antennae on head
(Examples: Locusts, Mosquitos, Cockroaches)
2. Arachnids
 8 jointed legs
 Don’t have wings or antennae
(Examples: Spiders, Scorpions, Ticks)
3. Crustaceans
 With tough exoskeleton
 More than 4 pairs of jointed legs
 2 pairs of antennae
(Examples: Lobsters, Crabs, Shrimps)
4. Myriapods
 Many pairs of jointed legs
 One pair of antennae
(Examples: Centipedes, Millipedes, Symphyla)
Conduction, convection, and radiation
Conduction
Transfer of heat from a hot place to a cooler one through a heat conductor.
Example:
Common heat conductors (Usually metals)
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Aluminium
Bronze
Copper
Iron
Convection
Transfer of hear by the motion of a fluid (Example: Air, Water)
Basic principle of heat convection
Warmer fluids rise, cooler fluids sink
Example:
*Convection currents are the constant cyclical motion of air
*Natural wind is caused by convection
Radiation
Transfer of heat through energy emitted by matter in the form of electromagnetic waves
Example:
*Heat is transferred from the Sun to Earth through radiation
*Most heat transfers through radiation are in Infrared waves
*Black surfaces absorb radiation
*Shiny white/ Silver surfaces reflect radiation
Energy (renewable or non-renewable)
Renewable energy
Energy that cannot be used up and can be replaced naturally
Examples:
1. Wind Power
 Wind can turn a windmill, which turns a turbine and generates electricity
2. Water power
 Water can turn a mill wheel, which turns a turbine and generates electricity
3. Solar Energy
 The sun can be used to generate electricity using solar cells
4. Biofuels
 Biofuel can be fermented to produce liquid fuel for cars and trucks
Non-renewable energy
Energy that can be used up eventually
Examples:
1. Coal
 Takes millions of years to form
 Combustible
2. Nuclear energy
 Split atoms to gain energy
 Radioactive material can be used up
3. Petroleum
 Takes millions of years to form
 Combustible
4. Natural gas
 Formed deep beneath the Earth’s surface
 Combustible
Exothermic and endothermic
Exothermic reactions
Chemical reactions that release energy (heat)
(Examples: Potassium + Water, Carbon + Oxygen, )
Endothermic reaction
Chemical reactions that absorb energy
(Examples: Sodium Hydrogen Carbonate + Citric Acid, Ice Melting)
Moments
 The turning effect of a force
 Moment = Force x Distance from pivot
Principle of Moments
For a beam to be balanced:
Clockwise moment = Anticlockwise moment
Example:
Moment B = 500N x 2m
= 1000Nm
Moment A = 1000N x 1m
= 1000Nm
Clockwise moment = Anticlockwise moment ; Moment A = Moment B, therefore the beam is balanced.
Moment = Force x Distance
Force = Moment / Distance
Distance = Moment / Force
Heart circulatory system
Structure of a heart
1. Artery to lungs
 Sends deoxygenated blood to the lungs
2. Artery to body
 Sends oxygenated blood to the body
3. Vein from body
 Sends deoxygenated blood to the heart
4. Vein from lungs
 Sends oxygenated blood to the heart
5. Upper chamber
 Receive incoming blood
6. Valve
 Control the blood flow in the heart
7. Lower chamber
 Pump blood out of heat
Blood
Plasma
 Liquid part of the blood
 Contain many different substances dissolved
 Sugar is dissolved in plasma
Red blood cells
 Small
 Contain reg pigment (Haemoglobin)
 Oxygenated Haemoglobin (Oxyhaemoglobin) is very bright red
 Deoxygenated Haemoglobin (Haemoglobin) is dull blueish-red
White blood cells
 Larger than red blood cells
 Have a nucleus
 Defend against viruses and bacteria
 Produce enzymes and antibodies to kill bacterium
Platelets
 Clot and seal wounds
Blood vessels
The tubes through which blood flows. There are 3 main types of blood vessels.
Arteries
 Carries blood away from the heart
 Delivers blood to the body
 Thick, strong, elastic walls
 Have to withstand strong forces and pressures
Capillaries
 Very tiny
 Thin walls made of one layer of cells
 Supply cells with things they need
 Take away waste products
Veins
 Return blood to the heart
 Similar size to arteries
 Thinner walls
 Bigger space inside
 Contain valves
Reactivity of Metals
Reactivity series (Most reactive to least reactive)
 Potassium
 Sodium
 Lithium
 Calcium
 Magnesium
 Aluminium
 Zinc
 Iron
 Lead
 Copper
 Silver
 Gold
Food Chain
Trophic levels
Producers
 1st trophic level
 Usually plants
 Uses photosynthesis to create food
(Examples: Grass, leaves, weed)
Primary Consumers
 2nd trophic level
 Herbivores
 Consumes producers
(Examples: Caterpillars, insects, hummingbirds)
Secondary Consumers
 3rd trophic level
 2nd level consumer
 Carnivores
 Consumes primary consumers
 Some are omnivores, which consume producers & primary consumers
(Examples: Fox, frogs)