C1 1.1 ATOMS, ELEMENTS & COMPOUNDS
• All substances are made of atoms
• Elements are made of only one type of atom
• Compounds contain more than one type of atom
• Compounds are held together by bonds
An atom is
made up of
a tiny
nucleus
with
electrons
around it
• Each element has its own
symbol in the periodic table
• Columns are called GROUPS.
• Elements in a group have
similar properties
• Rows are called PERIODS
• The red staircase splits
metals from non-metals
C1 1.2 ATOMIC STRUCTURE
• Atoms contain PROTONS, NEUTRONS & ELECTRONS
• Protons and Neutrons are found in the NUCLEUS
• Electrons orbit the nucleus
PARTICLE
RELATIVE
CHARGE
RELATIVE
MASS
Proton
+1 (positive)
1
Neutron
0 (neutral)
1
Electron
-1 (negative)
0
Any atom contains equal numbers of
protons and electrons
• ATOMIC NUMBER  the number of protons in the nucleus
 the periodic table is arranged in this order
• MASS NUMBER  the number of protons plus neutrons
Number of neutrons = Mass Number – Atomic Number
C1 1.3 ELECTRON ARRANGEMENT
• Electrons are arranged around the nucleus in SHELLS (or energy levels)
• The shell closest to the nucleus has the lowest energy
• Electrons occupy the lowest available energy level
High energy shell
This is how we draw atoms
and their electrons
Sodium
Low energy shell
• Atoms with the same number of electrons in the outer shell belong to the same GROUP in
the periodic table
• Number of outer electrons determine the way an element reacts
• Atoms of the last group (noble gases) have stable arrangements and are unreactive
C1 1.4 FORMING BONDS
•
Atoms can react to form compounds in a number of ways:
i)
Transferring electrons  IONIC BONDING
ii)
Sharing electrons  COVALENT BONDING
IONIC BONDING
COVALENT BONDING
• When a metal and non-metal react
• Metals form positive ions
• Non-metals from negative ions
• Opposite charges attract
• A giant lattice is formed
• When 2 non-metals bond
• Outermost electrons are shared
• A pair of shared electrons forms a bond
CHEMICAL FORMULAE
• Tells us the ratio of each element in the
compound
• In ionic compounds the charges must cancel
out:
E.g. MgCl2
We have 2 chloride ions for every magnesium ion
C1 1.5 CHEMICAL EQUATIONS
• Chemical equations show the reactants (what we start with) and the products (what we end
up with)
• We often use symbol equations to make life easier
CaCO3  CaO + CO2
Ca = 1
C=1
O=3
Ca = 1
C=1
O=3
• This is balanced – same number of each type of atom
on both sides of the equation
• We can check this by counting the number of each
type on either side
MAKING EQUATIONS BALANCE
Equations MUST balance
We can ONLY add BIG numbers to the front of
a substance
We can tell elements within a compound by BIG
letters
CaCO3  this is a compound made of 3 elements
(calcium, carbon and oxygen)
H2 + O2  H2O
H=2
O=2
H=2
O=1
Add a 2 to the products side to make the oxygen
balance
H2 + O2  2H2O
H=2
O=2
H=4
O=2
This has changed the number of hydrogen atoms
so we must now adjust the reactant side:
2H2 + O2  2H2O
C1 2.1 LIMESTONE & ITS USES
• Limestone is made mainly of Calcium Carbonate
• Calcium carbonate has the chemical formulae CaCO3
• Some types of limestone (e.g. chalk) were formed from the remains of animals and plants
that live millions of years ago
USE IN BUILDING
HEATING LIMESTONE
We use limestone in many buildings by cutting it
into blocks.
Breaking down a chemical by heating is
called THERMAL DECOMPOSITION
Other ways limestone is used:
Cement = powdered limestone + powdered clay
Concrete = Cement + Sand + Water
Calcium
 Calcium + Carbon
Carbonate
Oxide
Dioxide
CaCO3

CaO
+
CO2
ROTARY LIME KILN
This is the furnace used to heat lots of calcium carbonate and turn it into calcium oxide
Calcium oxide is used in the building and agricultural industries
C1 2.2 REACTIONS OF CARBONATES
• Buildings made from limestone suffer from damage by acid rain
• This is because carbonates react with acid to form a salt, water and carbon dioxide
Calcium + Hydrochloric  Calcium + Water + Carbon
Carbonate
Acid
Chloride
Dioxide
CaCO3 + 2HCl  CaCl2 + H2O + CO2
TESTING FOR CO2
• We use limewater to test for CO2
• Limewater turns cloudy
• A precipitate (tiny solid particles) of calcium
carbonate forms causing the cloudiness!
HEATING CARBONATES
Metal carbonates decompose on heating
to form the metal oxide and carbon
dioxide
MgCO3  MgO + CO2
C1 2.3 THE LIMESTONE REACTION CYCLE
• Limestone is used widely as a building material
• We can also use it to make other materials for the construction industry
Calcium Carbonate + Heat  Calcium Oxide
Calcium Oxide + Water  Calcium Hydroxide (Limewater)
Step 4: Add CO2
Ca(OH)2 + CO2  CaCO3 + H2O
Calcium Carbonate
Limestone
CaCO3  CaO + CO2
Calcium Oxide
Calcium Hydroxide
Solution
Step 2: Add a bit of
water
Step 3: Add more water & filter
Ca(OH0)2 + H2O  Ca(OH)2 (aq)
Step 1: Add Heat
CaO + H2O  Ca(OH)2
Calcium Hydroxide
C1 2.4 CEMENT & CONCRETE
CEMENT
Made by heating limestone with clay in a kiln
MORTAR
Made by mixing cement and sand with water
CONCRETE
Made by mixing crushed rocks or stones (called aggregate), cement and sand with water
C1 2.5 LIMESTONE ISSUES
BENEFITS
DRAWBACKS
• Provide jobs
• Destroys habitats
• Lead to improved roads
• Increased emissions
• Filled in to make fishing lakes or for
planting trees
• Noisy & Dusty
• Can be used as landfill sites when finished
with
• Dangerous areas for children
• Busier roads
• Ugly looking
C1 3.1 EXTRACTING METALS
• A metal compound within a rock is called an ORE
• The metal is often combined with oxygen
• Ores are mined from the ground and then purified
Whether it’s worth extracting a particular metal
depends on:

How easy it is to extract

How much metal the ore contains
The reactivity series helps us decide the best way
to extract a metal:
 Metals below carbon in the series can be
reduced by carbon to give the metal element
 Metals more reactive than carbon cannot be
extracted using carbon. Instead other
methods like ELECTROLYSIS must be used
THE REACTIVITY SERIES
C1 3.2 IRON & STEELS
• Iron Ore contains iron combined with oxygen
• We use a blast furnace and carbon to extract it (as it’s less reactive than carbon)
• Carbon REDUCES the iron oxide;
Iron (III) Oxide + Carbon  Iron + Carbon Dioxide
• Iron from the blast furnace contains impurities:
 Makes it hard and brittle
• A metal mixed with other elements
is called an ALLOY
 Can be run into moulds to form cast iron
 Used in stoves & man-hole covers
E.g. Steel  Iron with carbon and/or
other elements
• Removing all the carbon impurities gives
There are a number of types of steel
alloys:
us pure iron
 Soft and easily shaped
 Too soft for most uses
 Need to combine it with other elements
Carbon steels
 Low-alloy steels
 High-alloy steels
 Stainless steels
C1 3.3 ALUMINIUM & TITANIUM
Aluminium
Titanium
Property
• Shiny
• Light
• Low density
• Conducts electricity and energy
• Malleable – easily shaped
• Ductile – drawn into cables and wires
• Strong
• Resistant to corrosion
• High melting point – so can be used
at high temperatures
• Less dense than most metals
Use
• Drinks cans
• Cooking foil
• Saucepans
• High-voltage electricity cables
• Bicycles
• Aeroplanes and space vehicles
• High-performance aircraft
• Racing bikes
• Jet engines
• Parts of nuclear reactors
• Replacement hip joints
Extraction
Electrolysis
Displacement & Electrolysis
• Aluminium ore is mined and extracted.
• Alumminium oxide (the ore) is melted
• Electric current passed through at high
temperature
• Use sodium or potassium to displace
titanium from its ore
• Get sodium and magnesium from
electrolysis
 Expensive process – need lots of heat and
electricity
 Expensive – lots of steps involved,
& needs lots of heat and electricity
C1 3.4 EXTRACTING COPPER
COPPER-RICH ORES
LOW GRADE COPPER ORES
These contain lots of copper. There are 2 ways to
consider:
These contain smaller amount of
copper. There are 2 main ways:
1. Smelting
1. Phytomining
• 80% of copper is produced this way
• Heat copper ore strongly in a furnace with air
Copper + Oxygen  Copper + Sulphur
Sulphide
Dioxide
• Then use electrolysis to purify the copper
• Expensive as needs lots of heat and electricity
2. Copper Sulphate
• Add sulphuric acid to a copper ore
• Produces copper sulphate
• Extract copper using electrolysis or displacement
• Plants absorb copper ions from lowgrade ore
• Plants are burned
• Copper ions dissolved by adding
sulphuric acid
• Use displacement or electrolysis to
extract pure copper
2. Bioleaching
• Bacteria feed on low-grade ore
• These produce a waste product that
contains copper ions
• Use displacement or electrolysis to
extract pure copper
C1 3.5 USEFUL METALS
TRANSITION METALS
COPPER ALLOYS
•
Bronze – Copper + Tin
- Tough
- Resistant to corrosion
Found in the central block of the periodic table
Properties:
•
Good conductors of electricity and energy
•
Strong
•
Malleable – easily bent into shape
Uses:
•
Buildings
•
Transport (cars, trains etc)
•
Heating systems
•
Electrical wiring
Example: Copper
1. Water pipes – easily bent into shape, strong,
doesn’t react with water
2. Wires – ductile and conduct electricity
Brass – Copper + Zinc
- Harder but workable
ALUMINIUM ALLOYS
• Alloyed with a wide range of other
elements
• All have very different properties
• E.g. in aircraft or armour plating!
GOLD ALLOYS
• Usually add Copper to make
jewellery last longer
C1 3.6 METALLIC ISSUES
EXPLOITING ORES
BUILDING WITH METALS
Mining has many environmental consequences:
Benefits
• Scar the landscape
• Steel is strong for girders
• Noisy & Dusty
• Aluminium is corrosion resistant
• Destroy animal habitats
• Many are malleable
• Large heaps of waste rock
• Copper is a good conductor and not
reactive
• Make groundwater acidic
• Release gases that cause acid rain
RECYCLING METALS
• Recycling aluminium saves 95% of the energy
normally used to extract it!
• This saves money!
• Iron and steel are easily recycled. As they are
magnetic they are easily separated
• Copper can be recycled too – but it’s trickier as
it’s often alloyed with other elements
Drawbacks
• Iron & steel can rust
• Extraction causes pollution
• Metals are more expensive than
other materials like concrete
C1 4.1 FUELS FROM CRUDE OIL
CRUDE OIL
• A mixture of lots of different compounds
[A mixture is 2 or more elements or compounds that are not
chemically bonded together]
• We separate it into substances with similar boiling points
• These are called fractions
• This is done in a process called fractional distillation
HYDROCARBONS
Nearly all the compounds in crude oil are hydrocarbons
Most of these are saturated hydrocarbons called alkanes
Methane
CH4
Ethane
C2H6
Propane
C3H8
General formula for
an alkane is CnH(2n+2)
Butane
C4H10
C1 4.2 FRACTIONAL DISTILLATION
This is the process by which crude oil is separated
into fractions
 These are compounds with similar sized chains
 Process relies on the boiling points of these
compounds
 The properties a fraction has depend on the size
of their hydrocarbon chains
SHORT CHAINS ARE:
 Very flammable
 Have low boiling points
 Highly volatile (tend to turn into gases)
 Have low viscosity (they flow easily)
Crude oil fed in at the bottom
Long chains have the opposite of these!
Temperature decreases up the
column
Hydrocarbons with smaller chains
found nearer the top
C1 4.3 BURNING FUELS
COMPLETE COMBUSTION
POLLUTION
Lighter fractions from crude oil make good fuels
Fossil fuels also produce a number
of impurities when they are burnt
They release energy when they are oxidised  burnt
in oxygen:
propane + oxygen  carbon dioxide + water
These have negative effects on the
environment
The main pollutants are summarised
below
Sulphur Dioxide
Carbon Monoxide
Nitrogen Oxide
• Poisonous gas
• Produced when not
enough oxygen
• Poisonous
• It’s acidic
• Causes acid rain
• Causes engine
corrosion
• Poisonous gas
• Prevents your blood
carrying oxygen
around your body
• Trigger asthma
attacks
• Can cause acid rain
Particulates
• Tiny solid particles
• Contain carbon and
unburnt hydrocarbon
• Carried in the air
• Damage cells in our
lungs
• Cause cancer
C1 4.4 CLEANER FUELS
Burning fuels releases pollutants that spread throughout the atmosphere:
GLOBAL WARMING
GLOBAL DIMMING
• Caused by carbon dioxide
• Caused by particulates
• Causing the average global temperature to
increase
• Reflect sunlight back into space
• Not as much light gets through to the
Earth
SULPHUR DIOXIDE
• Caused by impurities in the fuel
CARBON MONOXIDE
Formed by incomplete combustion
• Affect asthma sufferers
• Cause acid rain  damages plants & buildings
CATALYTIC CONVERTERS
• Reduces the carbon monoxide and
nitrogen oxide produced
• They are expensive
• They don’t reduce the amount of
CO2
Carbon + Nitrogen  Carbon + Nitrogen
Monoxide
Oxide
Dioxide
C1 4.5 ALTERNATIVE FUELS
These are renewable fuels  sources of energy that could replace fossil fuels (coal, oil &
gas)
+
BIODIESEL
ETHANOL
HYDROGEN
• Less harmful to animals
• Easily made by
fermenting sugar cane
• Very clean – no
CO2
• Gives off CO2 but the
sugar cane it comes from
absorbs CO2 when
growing
• Water is the only
product
• Large areas of
farmland required
• Less food produced as
people use it for fuel
instead!
• Hydrogen is
explosive
• Takes up a large
volume  storage
becomes an issue
• Breaks down 5 × quicker
• Reduces particulates
• Making it produces other useful
products
•‘CO2 neutral’ – plants grown to
create it absorb the same amount
of CO2 generated when it’s burnt
-
•Large areas of farmland required
•Less food produced  Famine
•Destruction of habitats
•Freezes at low temps
C1 5.1 CRACKING HYDROCARBONS
CRACKING  Breaking down large hydrocarbon chains into smaller, more useful ones
CRACKING PROCESS
SATURATED OR UNSATURATED?
1.
Heat hydrocarbons to a high temp;
then either:
We can react products with bromine water
to test for saturation:
2.
Mix them with steam; OR
3.
Pass the over a hot catalyst
Positive Test:
Unsaturated + Bromine  COLOURLESS
hydrocarbon Water
EXAMPLE OF CRACKING
Cracking is a thermal decomposition reaction:
= ALKENES
800oC
C10H22
C5H12 + C3H6 + C2H4
Decane
Pentane
Propene
Ethene
ALKENES
• These are unsaturated hydrocarbons
• They contain a double bond
• Have the general formula  CnH2n
Negative Test:
Saturated + Bromine  NO RECTION
Hydrocarbon
Water
(orange)
= ALKANES
C1 5.2 POLYMERS FROM ALKENES
PLASTICS  Are made from lots of monomers joined together to make a polymer
MONOMERS
POLYMER
Poly(ethene)
Ethene
HOW DO MONOMERS JOIN TOGETHER?
•
•
•
Double bond between carbons ‘opens up’
Replaced by single bonds as thousands of monomers join up
It is called POLYMERISATION
Simplified way
of writing it:
n
‘n’ represent a large
repeating number
C1 5.3 NEW & USEFUL POLYMERS
DESIGNER POLYMER  Polymer made to do a specific job
Examples of uses for them:
• Dental fillings
• Linings for false teeth
• Packaging material
• Implants that release drugs slowly
SMART POLYMERS  Have their properties changed by light, temperature or other changes
in their surroundings
Light-Sensitive Plasters
Hydrogels
Shape memory polymers
• Top layer of plaster
peeled back
• Lower layer now exposed
to light
• Adhesive loses stickiness
• Peels easily off the skin
• Have cross-linking chains
• Makes a matrix that traps
water
• Act as wound dressings
• Let body heal in moist,
sterile conditions
• Good for burns
• Wound is stitched loosely
• Temperature of the body
makes the thread tighten
• Closes the wound up with
the right amount of force
C1 5.4 PLASTIC WASTE
NON-BIODEGRADABLE
RECYCLING
• Don’t break down
• Sort plastics into different types
• Litter the streets and
shores
• Harm wildlife
• Unsightly
• Last 100’s of years
• Melted down and made into new
products
• Fill up landfill sites
• Saves energy and resources…BUT
BIODEGRADABLE PLASTICS
• Plastics that break down easily
• Granules of
cornstarch are
built into the
plastic
• Microorganisms in
soil feed on
cornstarch
• This breaks the
plastic down
• Hard to transport and
• Need to be sorted into specific
types
DISADVANTAGES OF
BIODEGRADABLE PLASTICS
• Farmers sell crops like corn to
make plastics
• Demand for food goes up
• Food prices go up  less can
afford it  STARVATION
• Animal habitats destroyed to make
new farmland
C1 5.5 ETHANOL
There are 2 main ways to make ethanol
1) FERMENTATION
2) ETHENE
Sugar from plants is broken down by
enzymes in yeast
Hydration reaction  water is added
Ethene + Steam  Ethanol
Sugar + Yeast  Ethanol + Carbon Dioxide
80% of ethanol is made this way
C2H4
+ H2O  C2H5OH
+ Uses renewable resources
+ Continuous process – lots made!
+ Produces no waste products
-Takes longer to produce
- CO2 is given off
- Requires lots of heat and energy
- Relies on a non-renewable resource
USES FOR ETHANOL
H H
H-C-C-OH
H H
A molecule of ethanol
• Alcohol
• Perfume
• Rocket Fuel
• Solvents
• Antiseptic wipes
C1 6.1 EXTRACTING VEGETABLE OIL
There are 2 ways to extract vegetable oils from plants:
1) PRESSING
2) DISTILLATION
1.
2.
3.
4.
5.
1.
2.
3.
Farmers collect seeds from plants
Seeds are crushed and pressed
This extracts oil from them
Impurities are removed
Oil is processed to make it into a
useful product
FOOD AND FUEL
Vegetable oils are important foods:
• Provide important nutrients (e.g. vitamin E)
• Contain lots of energy  so can also be used
as fuels
• Unsaturated oils contain double bonds (C=C)
 they decolourise Bromine water
Plants are put into water and boiled
Oil and water evaporate together
Oil is collected by condensing (cooling
the gas vapours)
Lavender oil is one oil extracted this way
Food
Energy
(kJ)
Veg Oil
3900
Sugar
1700
Meat
1100
Table for info only – don’t
memorise it!
C1 6.2 COOKING WITH VEGETABLE OILS
COOKING IN OIL
•
•
•
•
•
•
Food cooks quicker
Outside becomes crispier
Inside becomes softer
Food absorbs some of the oil
Higher energy content
Too much is unhealthy
Double bonds converted to
single bonds
HARDENING VEGETABLE OILS
• Reacting vegetable oils with HYDROGEN
hardens them  increases melting points
• Makes them solid at room temperature 
makes them into spreads!
+
• Double bonds converted to single bonds
C=C  C-C
• Now called a HYDROGENATED OIL
60oC + Nickel catalyst
• Reaction occurs at 60oC with a nickel
catalyst
C1 6.3 EVERYDAY EMULSIONS
Oils do not dissolve in water
EMULSION EXAMPLES
Emulsion  Where oil and water are
dispersed (spread out) in each
other
1.
2.
3.
4.
5.
 These often have special
properties
Mayonnaise
Milk
Ice cream
Cosmetics – face cream, lipstick etc
Paint
EMULSIFIERS
• Stop water and oil separating out into
layers
Emulsifier
molecule
• Emulsifiers have 2 parts that make
them work:
Oil
droplet
1. Hydrophobic tail – is attracted
to oil
2. Hydrophilic head – is attracted
to water. It has a negative
charge
-
Water
C1 6.4 FOOD ISSUES
FOOD ADDITIVES
VEG OILS
Substance added to food to:
Unsaturated Fats:
•
•
•
•
•
•
•
•
Preserve it
Improve its taste
Improve its texture
Improve its appearance
Source of nutrients like vitamin E
Keep arteries clear
Reduce heart disease
Lower cholesterol levels
ANIMAL FATS
Saturated Fats:
E NUMBER
Additives approved for use in Europe
• Are not good for us
• Increase risk of heart disease
• Increase cholesterol
EMULSIFIERS
•
Improve texture and taste of foods
containing fats and oils
•
Makes them more palatable (tasty)
and tempting to eat!
E.g. chocolate!
C1 7.1 STRUCTURE OF THE EARTH
Atmosphere:
Crust:
Most lies within 10km of the
surface
Solid
Rest is within 100km but it’s hard to
judge!
6km beneath
oceans
35km beneath land
Core:
Made of nickel and iron
Mantle
Outer core is liquid
Behaves like a solid
Inner core is solid
Can flow very slowly
Radius is 3500km
Is about 3000km deep!
C1 7.2 THE RESTLESS EARTH
MOVING CONTINENTS
The Earth’s crust and upper mantle are cracked into a number of
pieces  TECTONIC PLATES
These are constantly moving - just very slowly
Motion is caused by CONVECTION CURRENTS in the mantle, due
to radioactive decay
PANGAEA
If you look at the continents they roughly fit together
Scientists think they were once one large land mass called
pangaea, which then broke off into smaller chunks
PLATE BOUNDARIES
Earthquakes and volcanoes
happen when tectonic plates
meet
These are very difficult to
predict
C1 7.3 THE EARTH’S ATMOSPHERE IN THE PAST
PHASE 1:
Volcanoes = Steam &
CO2
• Volcanoes kept erupting
giving out Steam and CO2
• The early atmosphere was
nearly all CO2
• The earth cooled and
water vapour condensed to
form the oceans
PHASE 2:
Green Plants,
Bacteria & Algae =
Oxygen
• Green plants, bacteria
and algae ran riot in the
oceans!
• Green plants steadily
converted CO2 into O2
by the process of
photosynthesis
• Nitrogen released by
denitrifying bacteria
• Plants colonise the land.
Oxygen levels steadily
increase
Like this
for a
billion
years!
PHASE 3:
Ozone Layer =
Animals & Us
• The build up of O2
killed off early
organisms - allowing
evolution of complex
organisms
• The O2 created the
Ozone layer (O3) which
blocks harmful UV rays
from the sun
• Virtually no CO2 left
C1 7.4 LIFE ON EARTH
No one can be sure how life on Earth first
started. There are many different theories:
MILLER-UREY EXPERIMENT
•
Compounds for life on Earth came from
reactions involving hydrocarbons (e.g.
methane) and ammonia
•
The energy for this could have been
provided by lightning
OTHER THEORIES
1. Molecules for life (amino acids) came on
meteorites from out of space
2. Actual living organisms themselves arrived on
meteorites
3. Biological molecules were released from deep
ocean vents
The experiment completed
by Miller and Urey
C1 7.5 GASES IN THE ATMOSPHERE
THE ATMOSPHERE TODAY:
CARBON DIOXIDE:
• Taken in by plants during photosynthesis
• When plants and animals die carbon is
transferred to rocks
• Some forms fossil fuels which are released
into the atmosphere when burnt
The main gases in air
can be separated out
by fractional
distillation.
The main gases in the atmosphere today are:
1.
2.
3.
4.
Nitrogen  78%
Oxygen  21%
Argon  0.9%
Carbon Dioxide  0.04%
These gases are
useful in industry
C1 7.6 CARBON DIOXIDE IN THE ATMOSPHERE
The stages in the cycle are shown below:
Carbon moves into and out of
the atmosphere due to
• Plants – photosynthesis &
decay
• Animals – respiration &
decay
• Oceans – store CO2
• Rocks – store CO2 and
release it when burnt
CO2 LEVELS
Have increased in the
atmosphere recently
largely due to the
amount of fossil fuels we
now burn
C1
Products
from oil
Ethene
(C2H4)
Cracking involves breaking down
larger crude oil fractions into
smaller
more
useful
hydrocarbons.
Propene
(C3H6)
Alkenes are produced during
cracking. These are
unsaturated hydrocarbons
which means they contain a
double bond. Their general
formula is CnH2n
Bromine water can be used to test a
compound to see if its an alkane or
alkene. It stays orange if a compound is
saturated. It turns colourless if a
compound is unsaturated.
PET is the plastic used for
drinks bottles because it is
strong, light, waterproof and
transparent. These properties
mean it can be recycled for
hiking jackets.
Biodegradable plastics are made partly
using corn starch, which microorganisms
feed on to break it down. However, growing
corn starch for fuel and plastics could raise
food prices, destroy habitats and cause
global warming.
Here is an example of cracking:
800°C + Catalyst
C10H22 ----------------------> C5H12
Decane
Pentane
Crude oil can be used to make plastics
using a process called polymerisation.
This process involves joining together
small molecules known as monomers
into large molecules known as polymers.
Smart polymers like shape
memory polymers, change
shape when they are hot or
cold. Stitches that tighten due to
the body’s temperature and
then later dissolve are being
developed.
Cracking is a thermal
decomposition reaction large molecules are broken
into smaller molecules
using heat
This reaction involves heating the
crude oil fraction to a high
temperature so that it vaporises. The
vapour is then passed over a catalyst
or mixed with steam.
C3H6 + C2H4
Propene
Ethene
Ethene can be polymerised to make
(poly)ethene, used for carrier bags and drinks
bottles because it strong and transparent.
Propene can be polymerised to form
(poly)propene, a strong and tough plastic used
for carpets and rope.
Designer polymers are
materials that chemists
make with specific
properties for a certain
job. Light sensitive
plasters cause less pain
when removed.
Ethanol is an alcohol. Ethanol for use in
drinks is made by fermentation of sugar
using yeast:
sugar---------->ethanol + carbon dioxide
The ethanol is produced in batches and
gives off CO2, a greenhouse gas.
+
Polymerisation of ethene can
represented like this:
Ethanol for use as a fuel or a solvent
can be made from ethene and steam.
This is a hydration reaction. It does not
give off CO2 and is a continuous
process. However, ethene comes from
crude oil, which means it is a nonrenewable production method.
C1
Products
from oil
___________involves
breaking
down larger crude oil fractions
into _________ more _______
hydrocarbons.
_______ are produced during
cracking. These are
__________ hydrocarbons
which means they contain a
________ bond. Their general
formula is _______
Ethene
(C2H4)
__________ can be used to test a
compound to see if its an alkane or
alkene. It stays _______ if a compound
is
____________
It
turns
____________ if a compound is
______________.
PET is the plastic used for
drinks bottles because it is
______, _______, _______
and _______. These
properties mean it can be
________for hiking ______.
___________ plastics are made partly using
_________, which ___________ feed on to
break it down. However, growing corn
starch for ____and ______ could raise
_________, destroy _______ and cause
______________.
Here is an example of cracking:
800°C + Catalyst
C10H22 ----------------------> C5H12 +
+ C2H4
Decane
_______ Propene
______
Crude oil can be used to make plastics
using a process called __________. This
process involves joining together small
molecules known as __________ into
large molecules known as ___________.
_______polymers like ________
_______polymers, change
shape when they are hot or
cold. Stitches that tighten due to
the body’s ___________and
then later ______ are being
developed.
Cracking is a _________
________ reaction - ____
molecules are broken into
_______ molecules using
_______
This reaction involves heating the
crude oil fraction to a high
___________so that it ________.
The vapour is then passed over a
_________ or mixed with _____.
Ethene can be polymerised to make
________________ used for carrier bags and
drinks bottles because it _________ and
____________. Propene can be polymerised to
form _____________ a strong and tough plastic
used for _______ and ________.
_____________are
materials that chemists
make with specific
properties for a certain
job. _________plasters
cause less pain when
removed.
_________ is an ________. Ethanol for
use in drinks is made by ___________of
sugar using ______.
sugar---------->ethanol + carbon dioxide
The ethanol is produced in ______and
gives off CO2, a greenhouse gas.
Polymerisation of ethene can
represented like this:
Ethanol for use as a fuel or a solvent
can be made from ________and
_______. This is a _________ reaction.
It does not give off ___ and is a
_________ process. However, ethene
comes from _______ which means it is
a _____________ production method.
C1 1.1 ATOMS, ELEMENTS & COMPOUNDS
• All substances are made of atoms
• Elements are made of only one type of atom
• Compounds contain more than one type of atom
• Compounds are held together by bonds
An atom is
made up of
a tiny
nucleus
with
electrons
around it
• Each element has its own
symbol in the periodic table
• Columns are called GROUPS.
• Elements in a group have
similar properties
• Rows are called PERIODS
• The red staircase splits
metals from non-metals
C1 1.2 ATOMIC STRUCTURE
• Atoms contain PROTONS, NEUTRONS & ELECTRONS
• Protons and Neutrons are found in the NUCLEUS
• Electrons orbit the nucleus
PARTICLE
RELATIVE
CHARGE
RELATIVE
MASS
Proton
+1 (positive)
1
Neutron
0 (neutral)
1
Electron
-1 (negative)
0
Any atom contains equal numbers of
protons and electrons
• ATOMIC NUMBER  the number of protons in the nucleus
 the periodic table is arranged in this order
• MASS NUMBER  the number of protons plus neutrons
Number of neutrons = Mass Number – Atomic Number
C1 1.3 ELECTRON ARRANGEMENT
• Electrons are arranged around the nucleus in SHELLS (or energy levels)
• The shell closest to the nucleus has the lowest energy
• Electrons occupy the lowest available energy level
High energy shell
This is how we draw atoms
and their electrons
Sodium
Low energy shell
• Atoms with the same number of electrons in the outer shell belong to the same GROUP in
the periodic table
• Number of outer electrons determine the way an element reacts
• Atoms of the last group (noble gases) have stable arrangements and are unreactive
C1 1.4 FORMING BONDS
•
Atoms can react to form compounds in a number of ways:
i)
Transferring electrons  IONIC BONDING
ii)
Sharing electrons  COVALENT BONDING
IONIC BONDING
COVALENT BONDING
• When a metal and non-metal react
• Metals form positive ions
• Non-metals from negative ions
• Opposite charges attract
• A giant lattice is formed
• When 2 non-metals bond
• Outermost electrons are shared
• A pair of shared electrons forms a bond
CHEMICAL FORMULAE
• Tells us the ratio of each element in the
compound
• In ionic compounds the charges must cancel
out:
E.g. MgCl2
We have 2 chloride ions for every magnesium ion
C1 1.5 CHEMICAL EQUATIONS
• Chemical equations show the reactants (what we start with) and the products (what we end
up with)
• We often use symbol equations to make life easier
CaCO3  CaO + CO2
Ca = 1
C=1
O=3
Ca = 1
C=1
O=3
• This is balanced – same number of each type of atom
on both sides of the equation
• We can check this by counting the number of each
type on either side
MAKING EQUATIONS BALANCE
Equations MUST balance
We can ONLY add BIG numbers to the front of
a substance
We can tell elements within a compound by BIG
letters
CaCO3  this is a compound made of 3 elements
(calcium, carbon and oxygen)
H2 + O2  H2O
H=2
O=2
H=2
O=1
Add a 2 to the products side to make the oxygen
balance
H2 + O2  2H2O
H=2
O=2
H=4
O=2
This has changed the number of hydrogen atoms
so we must now adjust the reactant side:
2H2 + O2  2H2O
C1 2.1 LIMESTONE & ITS USES
• Limestone is made mainly of Calcium Carbonate
• Calcium carbonate has the chemical formulae CaCO3
• Some types of limestone (e.g. chalk) were formed from the remains of animals and plants
that live millions of years ago
USE IN BUILDING
HEATING LIMESTONE
We use limestone in many buildings by cutting it
into blocks.
Breaking down a chemical by heating is
called THERMAL DECOMPOSITION
Other ways limestone is used:
Cement = powdered limestone + powdered clay
Concrete = Cement + Sand + Water
Calcium
 Calcium + Carbon
Carbonate
Oxide
Dioxide
CaCO3

CaO
+
CO2
ROTARY LIME KILN
This is the furnace used to heat lots of calcium carbonate and turn it into calcium oxide
Calcium oxide is used in the building and agricultural industries
C1 2.2 REACTIONS OF CARBONATES
• Buildings made from limestone suffer from damage by acid rain
• This is because carbonates react with acid to form a salt, water and carbon dioxide
Calcium + Hydrochloric  Calcium + Water + Carbon
Carbonate
Acid
Chloride
Dioxide
CaCO3 + 2HCl  CaCl2 + H2O + CO2
TESTING FOR CO2
• We use limewater to test for CO2
• Limewater turns cloudy
• A precipitate (tiny solid particles) of calcium
carbonate forms causing the cloudiness!
HEATING CARBONATES
Metal carbonates decompose on heating
to form the metal oxide and carbon
dioxide
MgCO3  MgO + CO2
C1 2.3 THE LIMESTONE REACTION CYCLE
• Limestone is used widely as a building material
• We can also use it to make other materials for the construction industry
Calcium Carbonate + Heat  Calcium Oxide
Calcium Oxide + Water  Calcium Hydroxide (Limewater)
Step 4: Add CO2
Ca(OH)2 + CO2  CaCO3 + H2O
Calcium Carbonate
Limestone
CaCO3  CaO + CO2
Calcium Oxide
Calcium Hydroxide
Solution
Step 2: Add a bit of
water
Step 3: Add more water & filter
Ca(OH0)2 + H2O  Ca(OH)2 (aq)
Step 1: Add Heat
CaO + H2O  Ca(OH)2
Calcium Hydroxide
C1 2.4 CEMENT & CONCRETE
CEMENT
Made by heating limestone with clay in a kiln
MORTAR
Made by mixing cement and sand with water
CONCRETE
Made by mixing crushed rocks or stones (called aggregate), cement and sand with water
C1 2.5 LIMESTONE ISSUES
BENEFITS
DRAWBACKS
• Provide jobs
• Destroys habitats
• Lead to improved roads
• Increased emissions
• Filled in to make fishing lakes or for
planting trees
• Noisy & Dusty
• Can be used as landfill sites when finished
with
• Dangerous areas for children
• Busier roads
• Ugly looking
C1 3.1 EXTRACTING METALS
• A metal compound within a rock is called an ORE
• The metal is often combined with oxygen
• Ores are mined from the ground and then purified
Whether it’s worth extracting a particular metal
depends on:

How easy it is to extract

How much metal the ore contains
The reactivity series helps us decide the best way
to extract a metal:
 Metals below carbon in the series can be
reduced by carbon to give the metal element
 Metals more reactive than carbon cannot be
extracted using carbon. Instead other
methods like ELECTROLYSIS must be used
THE REACTIVITY SERIES
C1 3.2 IRON & STEELS
• Iron Ore contains iron combined with oxygen
• We use a blast furnace and carbon to extract it (as it’s less reactive than carbon)
• Carbon REDUCES the iron oxide;
Iron (III) Oxide + Carbon  Iron + Carbon Dioxide
• Iron from the blast furnace contains impurities:
 Makes it hard and brittle
• A metal mixed with other elements
is called an ALLOY
 Can be run into moulds to form cast iron
 Used in stoves & man-hole covers
E.g. Steel  Iron with carbon and/or
other elements
• Removing all the carbon impurities gives
There are a number of types of steel
alloys:
us pure iron
 Soft and easily shaped
 Too soft for most uses
 Need to combine it with other elements
Carbon steels
 Low-alloy steels
 High-alloy steels
 Stainless steels
C1 3.3 ALUMINIUM & TITANIUM
Aluminium
Titanium
Property
• Shiny
• Light
• Low density
• Conducts electricity and energy
• Malleable – easily shaped
• Ductile – drawn into cables and wires
• Strong
• Resistant to corrosion
• High melting point – so can be used
at high temperatures
• Less dense than most metals
Use
• Drinks cans
• Cooking foil
• Saucepans
• High-voltage electricity cables
• Bicycles
• Aeroplanes and space vehicles
• High-performance aircraft
• Racing bikes
• Jet engines
• Parts of nuclear reactors
• Replacement hip joints
Extraction
Electrolysis
Displacement & Electrolysis
• Aluminium ore is mined and extracted.
• Alumminium oxide (the ore) is melted
• Electric current passed through at high
temperature
• Use sodium or potassium to displace
titanium from its ore
• Get sodium and magnesium from
electrolysis
 Expensive process – need lots of heat and
electricity
 Expensive – lots of steps involved,
& needs lots of heat and electricity
C1 3.4 EXTRACTING COPPER
COPPER-RICH ORES
LOW GRADE COPPER ORES
These contain lots of copper. There are 2 ways to
consider:
These contain smaller amount of
copper. There are 2 main ways:
1. Smelting
1. Phytomining
• 80% of copper is produced this way
• Heat copper ore strongly in a furnace with air
Copper + Oxygen  Copper + Sulphur
Sulphide
Dioxide
• Then use electrolysis to purify the copper
• Expensive as needs lots of heat and electricity
2. Copper Sulphate
• Add sulphuric acid to a copper ore
• Produces copper sulphate
• Extract copper using electrolysis or displacement
• Plants absorb copper ions from lowgrade ore
• Plants are burned
• Copper ions dissolved by adding
sulphuric acid
• Use displacement or electrolysis to
extract pure copper
2. Bioleaching
• Bacteria feed on low-grade ore
• These produce a waste product that
contains copper ions
• Use displacement or electrolysis to
extract pure copper
C1 3.5 USEFUL METALS
TRANSITION METALS
COPPER ALLOYS
•
Bronze – Copper + Tin
- Tough
- Resistant to corrosion
Found in the central block of the periodic table
Properties:
•
Good conductors of electricity and energy
•
Strong
•
Malleable – easily bent into shape
Uses:
•
Buildings
•
Transport (cars, trains etc)
•
Heating systems
•
Electrical wiring
Example: Copper
1. Water pipes – easily bent into shape, strong,
doesn’t react with water
2. Wires – ductile and conduct electricity
Brass – Copper + Zinc
- Harder but workable
ALUMINIUM ALLOYS
• Alloyed with a wide range of other
elements
• All have very different properties
• E.g. in aircraft or armour plating!
GOLD ALLOYS
• Usually add Copper to make
jewellery last longer
C1 3.6 METALLIC ISSUES
EXPLOITING ORES
BUILDING WITH METALS
Mining has many environmental consequences:
Benefits
• Scar the landscape
• Steel is strong for girders
• Noisy & Dusty
• Aluminium is corrosion resistant
• Destroy animal habitats
• Many are malleable
• Large heaps of waste rock
• Copper is a good conductor and not
reactive
• Make groundwater acidic
• Release gases that cause acid rain
RECYCLING METALS
• Recycling aluminium saves 95% of the energy
normally used to extract it!
• This saves money!
• Iron and steel are easily recycled. As they are
magnetic they are easily separated
• Copper can be recycled too – but it’s trickier as
it’s often alloyed with other elements
Drawbacks
• Iron & steel can rust
• Extraction causes pollution
• Metals are more expensive than
other materials like concrete
C1 4.1 FUELS FROM CRUDE OIL
CRUDE OIL
• A mixture of lots of different compounds
[A mixture is 2 or more elements or compounds that are not
chemically bonded together]
• We separate it into substances with similar boiling points
• These are called fractions
• This is done in a process called fractional distillation
HYDROCARBONS
Nearly all the compounds in crude oil are hydrocarbons
Most of these are saturated hydrocarbons called alkanes
Methane
CH4
Ethane
C2H6
Propane
C3H8
General formula for
an alkane is CnH(2n+2)
Butane
C4H10
C1 4.2 FRACTIONAL DISTILLATION
This is the process by which crude oil is separated
into fractions
 These are compounds with similar sized chains
 Process relies on the boiling points of these
compounds
 The properties a fraction has depend on the size
of their hydrocarbon chains
SHORT CHAINS ARE:
 Very flammable
 Have low boiling points
 Highly volatile (tend to turn into gases)
 Have low viscosity (they flow easily)
Crude oil fed in at the bottom
Long chains have the opposite of these!
Temperature decreases up the
column
Hydrocarbons with smaller chains
found nearer the top
C1 4.3 BURNING FUELS
COMPLETE COMBUSTION
POLLUTION
Lighter fractions from crude oil make good fuels
Fossil fuels also produce a number
of impurities when they are burnt
They release energy when they are oxidised  burnt
in oxygen:
propane + oxygen  carbon dioxide + water
These have negative effects on the
environment
The main pollutants are summarised
below
Sulphur Dioxide
Carbon Monoxide
Nitrogen Oxide
• Poisonous gas
• Produced when not
enough oxygen
• Poisonous
• It’s acidic
• Causes acid rain
• Causes engine
corrosion
• Poisonous gas
• Prevents your blood
carrying oxygen
around your body
• Trigger asthma
attacks
• Can cause acid rain
Particulates
• Tiny solid particles
• Contain carbon and
unburnt hydrocarbon
• Carried in the air
• Damage cells in our
lungs
• Cause cancer
C1 4.4 CLEANER FUELS
Burning fuels releases pollutants that spread throughout the atmosphere:
GLOBAL WARMING
GLOBAL DIMMING
• Caused by carbon dioxide
• Caused by particulates
• Causing the average global temperature to
increase
• Reflect sunlight back into space
• Not as much light gets through to the
Earth
SULPHUR DIOXIDE
• Caused by impurities in the fuel
CARBON MONOXIDE
Formed by incomplete combustion
• Affect asthma sufferers
• Cause acid rain  damages plants & buildings
CATALYTIC CONVERTERS
• Reduces the carbon monoxide and
nitrogen oxide produced
• They are expensive
• They don’t reduce the amount of
CO2
Carbon + Nitrogen  Carbon + Nitrogen
Monoxide
Oxide
Dioxide
C1 4.5 ALTERNATIVE FUELS
These are renewable fuels  sources of energy that could replace fossil fuels (coal, oil &
gas)
+
BIODIESEL
ETHANOL
HYDROGEN
• Less harmful to animals
• Easily made by
fermenting sugar cane
• Very clean – no
CO2
• Gives off CO2 but the
sugar cane it comes from
absorbs CO2 when
growing
• Water is the only
product
• Large areas of
farmland required
• Less food produced as
people use it for fuel
instead!
• Hydrogen is
explosive
• Takes up a large
volume  storage
becomes an issue
• Breaks down 5 × quicker
• Reduces particulates
• Making it produces other useful
products
•‘CO2 neutral’ – plants grown to
create it absorb the same amount
of CO2 generated when it’s burnt
-
•Large areas of farmland required
•Less food produced  Famine
•Destruction of habitats
•Freezes at low temps
C1 5.1 CRACKING HYDROCARBONS
CRACKING  Breaking down large hydrocarbon chains into smaller, more useful ones
CRACKING PROCESS
SATURATED OR UNSATURATED?
1.
Heat hydrocarbons to a high temp;
then either:
We can react products with bromine water
to test for saturation:
2.
Mix them with steam; OR
3.
Pass the over a hot catalyst
Positive Test:
Unsaturated + Bromine  COLOURLESS
hydrocarbon Water
EXAMPLE OF CRACKING
Cracking is a thermal decomposition reaction:
= ALKENES
800oC
C10H22
C5H12 + C3H6 + C2H4
Decane
Pentane
Propene
Ethene
ALKENES
• These are unsaturated hydrocarbons
• They contain a double bond
• Have the general formula  CnH2n
Negative Test:
Saturated + Bromine  NO RECTION
Hydrocarbon
Water
(orange)
= ALKANES
C1 5.2 POLYMERS FROM ALKENES
PLASTICS  Are made from lots of monomers joined together to make a polymer
MONOMERS
POLYMER
Poly(ethene)
Ethene
HOW DO MONOMERS JOIN TOGETHER?
•
•
•
Double bond between carbons ‘opens up’
Replaced by single bonds as thousands of monomers join up
It is called POLYMERISATION
Simplified way
of writing it:
n
‘n’ represent a large
repeating number
C1 5.3 NEW & USEFUL POLYMERS
DESIGNER POLYMER  Polymer made to do a specific job
Examples of uses for them:
• Dental fillings
• Linings for false teeth
• Packaging material
• Implants that release drugs slowly
SMART POLYMERS  Have their properties changed by light, temperature or other changes
in their surroundings
Light-Sensitive Plasters
Hydrogels
Shape memory polymers
• Top layer of plaster
peeled back
• Lower layer now exposed
to light
• Adhesive loses stickiness
• Peels easily off the skin
• Have cross-linking chains
• Makes a matrix that traps
water
• Act as wound dressings
• Let body heal in moist,
sterile conditions
• Good for burns
• Wound is stitched loosely
• Temperature of the body
makes the thread tighten
• Closes the wound up with
the right amount of force
C1 5.4 PLASTIC WASTE
NON-BIODEGRADABLE
RECYCLING
• Don’t break down
• Sort plastics into different types
• Litter the streets and
shores
• Harm wildlife
• Unsightly
• Last 100’s of years
• Melted down and made into new
products
• Fill up landfill sites
• Saves energy and resources…BUT
BIODEGRADABLE PLASTICS
• Plastics that break down easily
• Granules of
cornstarch are
built into the
plastic
• Microorganisms in
soil feed on
cornstarch
• This breaks the
plastic down
• Hard to transport and
• Need to be sorted into specific
types
DISADVANTAGES OF
BIODEGRADABLE PLASTICS
• Farmers sell crops like corn to
make plastics
• Demand for food goes up
• Food prices go up  less can
afford it  STARVATION
• Animal habitats destroyed to make
new farmland
C1 5.5 ETHANOL
There are 2 main ways to make ethanol
1) FERMENTATION
2) ETHENE
Sugar from plants is broken down by
enzymes in yeast
Hydration reaction  water is added
Ethene + Steam  Ethanol
Sugar + Yeast  Ethanol + Carbon Dioxide
80% of ethanol is made this way
C2H4
+ H2O  C2H5OH
+ Uses renewable resources
+ Continuous process – lots made!
+ Produces no waste products
-Takes longer to produce
- CO2 is given off
- Requires lots of heat and energy
- Relies on a non-renewable resource
USES FOR ETHANOL
H H
H-C-C-OH
H H
A molecule of ethanol
• Alcohol
• Perfume
• Rocket Fuel
• Solvents
• Antiseptic wipes
C1 6.1 EXTRACTING VEGETABLE OIL
There are 2 ways to extract vegetable oils from plants:
1) PRESSING
2) DISTILLATION
1.
2.
3.
4.
5.
1.
2.
3.
Farmers collect seeds from plants
Seeds are crushed and pressed
This extracts oil from them
Impurities are removed
Oil is processed to make it into a
useful product
FOOD AND FUEL
Vegetable oils are important foods:
• Provide important nutrients (e.g. vitamin E)
• Contain lots of energy  so can also be used
as fuels
Plants are put into water and boiled
Oil and water evaporate together
Oil is collected by condensing (cooling
the gas vapours)
Lavender oil is one oil extracted this way
Food
Energy
(kJ)
Veg Oil
3900
Sugar
1700
Meat
1100
• Unsaturated oils contain double bonds (C=C)
 they decolourise Bromine water
Table for info only – don’t
memorise it!
C1 6.2 COOKING WITH VEGETABLE OILS
COOKING IN OIL
•
•
•
•
•
•
Food cooks quicker
Outside becomes crispier
Inside becomes softer
Food absorbs some of the oil
Higher energy content
Too much is unhealthy
Double bonds converted to
single bonds
HARDENING VEGETABLE OILS
• Reacting vegetable oils with HYDROGEN
hardens them  increases melting points
• Makes them solid at room temperature 
makes them into spreads!
+
• Double bonds converted to single bonds
C=C  C-C
• Now called a HYDROGENATED OIL
60oC + Nickel catalyst
• Reaction occurs at 60oC with a nickel
catalyst
C1 6.3 EVERYDAY EMULSIONS
Oils do not dissolve in water
EMULSION EXAMPLES
Emulsion  Where oil and water are
dispersed (spread out) in each
other
1.
2.
3.
4.
5.
 These often have special
properties
Mayonnaise
Milk
Ice cream
Cosmetics – face cream, lipstick etc
Paint
EMULSIFIERS
• Stop water and oil separating out into
layers
Emulsifier
molecule
• Emulsifiers have 2 parts that make
them work:
Oil
droplet
1. Hydrophobic tail – is attracted
to oil
2. Hydrophilic head – is attracted
to water. It has a negative
charge
-
Water
C1 6.4 FOOD ISSUES
FOOD ADDITIVES
VEG OILS
Substance added to food to:
Unsaturated Fats:
•
•
•
•
•
•
•
•
Preserve it
Improve its taste
Improve its texture
Improve its appearance
Source of nutrients like vitamin E
Keep arteries clear
Reduce heart disease
Lower cholesterol levels
ANIMAL FATS
Saturated Fats:
E NUMBER
Additives approved for use in Europe
• Are not good for us
• Increase risk of heart disease
• Increase cholesterol
EMULSIFIERS
•
Improve texture and taste of foods
containing fats and oils
•
Makes them more palatable (tasty)
and tempting to eat!
E.g. chocolate!
C1 7.1 STRUCTURE OF THE EARTH
Atmosphere:
Crust:
Most lies within 10km of the
surface
Solid
Rest is within 100km but it’s hard to
judge!
6km beneath
oceans
35km beneath land
Core:
Made of nickel and iron
Mantle
Outer core is liquid
Behaves like a solid
Inner core is solid
Can flow very slowly
Radius is 3500km
Is about 3000km deep!
C1 7.2 THE RESTLESS EARTH
MOVING CONTINENTS
The Earth’s crust and upper mantle are cracked into a number of
pieces  TECTONIC PLATES
These are constantly moving - just very slowly
Motion is caused by CONVECTION CURRENTS in the mantle, due
to radioactive decay
PANGAEA
If you look at the continents they roughly fit together
Scientists think they were once one large land mass called
pangaea, which then broke off into smaller chunks
PLATE BOUNDARIES
Earthquakes and volcanoes
happen when tectonic plates
meet
These are very difficult to
predict
C1 7.3 THE EARTH’S ATMOSPHERE IN THE PAST
PHASE 1:
Volcanoes = Steam & CO2
• Volcanoes kept erupting
giving out Steam and CO2
• The early atmosphere was
nearly all CO2
• The earth cooled and
water vapour condensed to
form the oceans
PHASE 2:
Green Plants, Bacteria
& Algae = Oxygen
• Green plants, bacteria
and algae ran riot in the
oceans!
• Green plants steadily
converted CO2 into O2
by the process of
photosynthesis
• Nitrogen released by
denitrifying bacteria
• Plants colonise the land.
Oxygen levels steadily
increase
Like this
for a
billion
years!
PHASE 3:
Ozone Layer =
Animals & Us
• The build up of O2
killed off early
organisms - allowing
evolution of complex
organisms
• The O2 created the
Ozone layer (O3) which
blocks harmful UV rays
from the sun
• Virtually no CO2 left
C1 7.4 LIFE ON EARTH
No one can be sure how life on Earth first
started. There are many different theories:
MILLER-UREY EXPERIMENT
•
Compounds for life on Earth came from
reactions involving hydrocarbons (e.g.
methane) and ammonia
•
The energy for this could have been
provided by lightning
OTHER THEORIES
1. Molecules for life (amino acids) came on
meteorites from out of space
2. Actual living organisms themselves arrived on
meteorites
3. Biological molecules were released from deep
ocean vents
The experiment completed
by Miller and Urey
C1 7.5 GASES IN THE ATMOSPHERE
THE ATMOSPHERE TODAY:
CARBON DIOXIDE:
• Taken in by plants during photosynthesis
• When plants and animals die carbon is
transferred to rocks
• Some forms fossil fuels which are released
into the atmosphere when burnt
The main gases in air
can be separated out
by fractional
distillation.
The main gases in the atmosphere today are:
1.
2.
3.
4.
Nitrogen  78%
Oxygen  21%
Argon  0.9%
Carbon Dioxide  0.04%
These gases are
useful in industry
C1 7.6 CARBON DIOXIDE IN THE ATMOSPHERE
The stages in the cycle are shown below:
Carbon moves into and out of
the atmosphere due to
• Plants – photosynthesis &
decay
• Animals – respiration &
decay
• Oceans – store CO2
• Rocks – store CO2 and
release it when burnt
CO2 LEVELS
Have increased in the
atmosphere recently
largely due to the
amount of fossil fuels we
now burn