What is meant by Combustion: Combustion is a chemical reaction that occurs between a fuel and an oxidizing agent that produces energy, usually in the form of heat and light.

What is meant by a fossil fuel:
A hydrocarbon deposit derived from living matter and used for fuel.

Fossil fuels: Oil, Coal, Natural gas and Peat. Peat is the accumulation of decayed plants.

Three requirements for a fire to begin: Oxygen, Heat and a Fuel.

What is the difference between complete and incomplete combustion:
Complete combustion released carbon dioxide and water, whilst incomplete released carbon dioxide, water AND carbon monoxide.

What poisonous gas is produced by fuels containing sulphur:
Sulphur Dioxide

Some harmful environmental effects of acid rain:
It can cause acidification of lakes and streams, and it can erode building materials.

What is meant by a finite source of energy and a renewable source of energy?
Finite = it cannot be replaced once it is used
Renewable = It can be constantly replaced.

What is meany by biomass:
Plant or animal based materials.

Two biofuels and how they can be produced:
Ethanol can be produced from sugar canes.
Bio Diesel can be produced from waste vegetables.

What is meant by a greenhouse gas:
Any gas in our atmosphere that is capable of absorbing heat. The most significant one is water vapour that contributes around 80% of all greenhouse gases.

What is meant by our carbon footprint:
The total sets of gas emissions caused by a product, person, organization or event.

What is meant by distillation:
A method of separating mixtures based on differences in the conditions required to change the components of the mixture.

Why is crude oil not of immediate use?
It is a mixture of hydrocarbons and they need to be separated to become useful products.

As the number of carbon atoms in a fraction increases, what happens to the colour and the ability of the fraction to ignite:
It gets darker, and it is more difficult to ignite.