10.6 The Atmosphere

10.6.2 State the gases that make up the atmosphere.

The atmosphere is made up of 3 main gases:

Nitrogen                    - 78%

Oxygen                      - 21%

Trace Gases              - 1%

10.6.4 Describe the variation of pressure as altitude increases.

As altitude increases, the atmospheric pressure decreases.

This means that the air pressure becomes lower the higher you go in the atmosphere.