Gases in the Atmosphere

The composition of gases in the air has stayed fairly constant over the past 200 million years. It is made up of a mixture of gases, with the two main components being nitrogen and oxygen.

  • 78% Nitrogen (N2)
  • 21% Oxygen (O2)

The remaining gases include:

  • Water vapour (H2O)
  • Carbon dioxide (CO2)
  • Trace amounts of the noble gases

The pie chart below shows the composition of gases in the atmosphere, excluding water vapour.

Pie chart showing the composition of gases in the atmosphere, with nitrogen constituting 78%, oxygen 21%, and other gases making up the remaining 1%.