1. Year 10 C1 – Chemistry and our Earth
Topic 1
The Earth is thought to be about 4.5 billion years old
Had volcanoes
Had volcanoes
98% nitrogen atmosphere
Mainly carbon dioxide atmosphere
Some scientists believe our atmosphere was like Titan
Titan
Some scientists believe our atmosphere was more like mars and venus
Mars and Venus
The two ways carbon dioxide was removed from the atmosphere was by dissolving in the oceans and through photosynthesis
The amount of oxygen in the atmosphere increased because photosynthesising organisms evolved, these release oxygen into the atmosphere and remove carbon dioxide from the atmosphere. Over time more and more photosynthesising organisms evolved so more oxygen was put into the atmosphere.
Atmosphere today
Examiners Tip
It is difficult to be certain how the planet has changed
Be clear about this when writing about theories and express alternative points of view

2. Types of rock Year 10 C1 – Chemistry and our Earth Topic 2 Igneous
granite
Year 10 C1 – Chemistry and our Earth
Topic 2
Chemical Reactions
In any reaction the total mass of products is the same as the total mass of the reactants
May become hot enough to partially melt
Contain crystals – size of crystal depends on rate at which it has cooled
Rocks deep inside the earth
Types of rock
Igneous
Metamorphic
Sedimentary
Molten rock is called magma
May erupt onto the surface as lava
Layers and layers of sediment build up along with the hard parts of dead organisms
Action of heat and pressure changes the rock forming new crystals
Thermal decomposition of limestone
Balanced equations show what happens to the atoms in a chemical reaction.
There needs to be equal numbers of each atom type on either side of the arrow!
The symbols (s) etc are state symbols showing the state that the chemical is in
limestone
Fossils may be found in sedimentary rock
Marble
Erosion happens when the rock is transported
Grains held tightly together
Rocks broken down by physical processes
Limestone undergoes thermal decomposition when heated. The same happens to other carbonates. For example, consider copper carbonate
Cement is made in a kiln
Limestone
Making buildings
Crushed to make a firm base for railway lines and roads
Raw material for cement, concrete and glass
Benefits and drawbacks of quarrying
Benefits
Drawbacks
Limestone is of commercial importance
Dusty and noisy (noise, traffic and pollution)
Provides jobs in rural areas which is helpful to families and local businesses.
Spoil landscapes (usually attractive places like the Peak District)
Limestone is valuable and can be exported- helps UK economy.
Affect quality of life of locals
Land can not be used for farming etc
Quarrying limestone
Limestone is removed from the ground in a quarry.
Explosives break the limestone into pieces- these are cut or crushed and transported to customers.
Cement is made by heating limestone with powdered clay
Concrete is made by mixing cement with sand, gravel and water

3. Year 10 C1 – Chemistry and our Earth
Topic 3
To test for oxygen: place a glowing splint in the mouth of the test tube. If the splint relights, you have oxygen!
To test for hydrogen: place a lit splint in the mouth of the test tube. If the test tube contains hydrogen (mixed with air) you will hear an explosion that sounds like a 'squeaky pop'.
Types of antacid
Since chlorine is toxic, a leak near a town could kill thousands.
45 million tonnes of chlorine are produced from seawater each year. Sometimes this can leak from a factory or tanker if there has been an accident.
Electrolysis can be used to break down an acid into its elements
Bleach is harmful to living things.
Antacids neutralise excess stomach acid.
Antacids contain bases- these are substances that react with acids.
The neutralisation reaction between an acid and a base produces water and a salt:
Acid + base → salt + water
Chlorine “bleaches” damp indicator paper. It is also a toxic gas so don’t breathe it! This leads to problems when it comes to large-scale manufacture of chlorine gas.
Manufacture plastics such as poly(chloroethene), also called PVC
recognisable smell
To treat our water supply (kills microbes)
Green toxic gas
It reacts with coloured substances to make them colourless (e.g. in paper making).
Uses of chlorine
Corrosive
Toxic
To manufacture bleach/other cleaning products
Flammable
Harmful or irritant

4. Year 10 C1 – Chemistry and our Earth
Topic 4
Reactivity of metals
The way in which a metal is extracted depends
This is the process of getting a metal from a
compound in a rock by a chemical reaction.
upon its reactivity.
Jewellery made from pure gold is very soft. Gold jewellery is usually made from alloys, in which gold is mixed with other metals
Gold!
Properties of metals
Stainless steel is an alloy that contains other metals such as Nickel and Chromium.
Stainless steel has the strength of steel combined with the corrosion resistance of nickel and the shininess of chromium
Shape memory alloys (e.g. Stent to keep a blocked blood vessel open)

5. Year 10 C1 – Chemistry and our Earth
Fuels
Year 10 C1 – Chemistry and our Earth
Topic 5 Part 1
These fuels are called “fossil fuels” and are described as being “non-renewable
Fractions with low boiling points condense at the top
Longer chains mean…
Less ability to flow
Less flammable
Less volatile
Higher boiling point
Increasing length
Coal
Wood
Oil
Fractions with high boiling points condense at the bottom
Gas
Crude oil is a mixture of HYDROCARBONS (compounds made up of carbon and hydrogen). Some examples:
Test for carbon dioxide
Burning a Fuel – Complete combustion
Distillation
CH O CO2 + 2H2O
Burning a Fuel –Incomplete combustion
This apparatus can be used to separate water and ink because they have different boiling points
Causes of acid Rain
Rainwater is naturally acidic
This is because carbon dioxide and other gases in the air dissolved in it
Acid rain has a pH lower than 5.2
Solutions to acid rain
Using low sulphur fuels
Removing acidic gases from factory fuel emissions

6. Year 10 C1 – Chemistry and our Earth
Topic 5 Part 2
Biodiesel is made from vegetable oils like oil seed rape or soya beans
Ethanol is made from wheat, sugar cane or sugar beet.
It can be made from fermenting sugar with yeast
Hydrogen as a fuel
Biodiesel can be used in diesel engine cars. These cars often use a mixture of diesel and biodiesel fuel beans
The ethanol can be mixed with petrol for use in car engines.
This reduces the demand for petrol
Advantages
Disadvantages
Hydrogen is non-polluting.
Costly to convert to liquid
Hydrogen has the highest energy content
Hydrogen is very reactive so difficult to store
Hydrogen is a renewable fuel source
Fossil Fuels May be Needed to Produce Hydrogen
Reduce dependency on foreign oil.