Lesson 4 of 7

The atmosphere

Goal: State what the air is made of.

Puzzles for this lesson

The atmosphere is the layer of gases around the Earth. Air is a mixture of gases, and most of it is nitrogen.

Nitrogen: about 78%. That is nearly four fifths of the air.
Oxygen: about 21%. That is about one fifth. Plants and animals need oxygen for aerobic respiration, and fuels need it to burn.
The last 1% is mostly argon. Carbon dioxide is only about 0.04% of the air. There are tiny amounts of other gases too.
These figures are for clean, dry air. Real air also holds some water vapour, and pollution can change the mixture a little.

Your turn

This lesson’s activity starts here in a moment.

I can give the percentages of nitrogen and oxygen.I can name two other gases in air.

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Atmosphere The layer of gases around the Earth

For teachers: AQA 3.7.3 · Pearson Edexcel 18.1 · Cambridge 7ESp.03