A gas is one of the three states of matter .

Gases fact file

Gases can be compressed (this means they are squashy)

Gases flow easily

Gases always completely fill any container they are placed in

The most common gas is called air

Some gases, like methane, burn easily and are used as fuels for heating

This table shows the names and uses of some common gases

Name of gas

Some useful facts



Air is the gas all around us.

It is a mixture of several different gases, mainly nitrogen and oxygen.

Without air we cannot breath and fires won’t burn.

It supports balloons and aeroplanes.

Natural Gas

Natural gas comes from the ground.

It burns easily (flammable)

Natural gas is used as a fuel for heating.


About 1/5 of the air is oxygen.

Without oxygen we cannot breath and fires wont burn.

Oxygen is produced by plants (during photosynthesis).

Oxygen is used in hospitals to help us breathe.

It also used in welding and as rocket fuel.

Carbon dioxide

Carbon dioxide is needed by plants when they make food (during photosynthesis).

All living organisms breath out carbon dioxide when they make energy (from food).

Carbon dioxide is the gas in fizzy drinks. It is also used in fire extinguishers.


Nitrogen is the main gas in air.
(about 80%)

Nitrogen is used to make plant food (fertilizer) and is also in explosives.

Water vapour

Water vapour is formed when water evaporates. There is lots of water vapour in the air we breathe out.

When water vapour in the air cools down it forms clouds.


There is a small amount of helium in the air.

It is a very light gas and is used in balloons to help them float

In balloons to help them float


There is a small amount of argon in the air.

Argon is the gas inside electric light bulbs

Quick test

Which gas is used up when things burn?  Answer

Which can get compressed the most, a solid, liquid or gas?  Answer

Name the most plentiful gas in the air? Answer

What gas is needed by plants to make food?  Answer

What gas is often put in fire extinuishers? Answer

Air does not weigh anything. True or False ? Answer