What is air? Name the major constituents of air. Also give their volume proportions in air.

Air is a mixture of gases. The major constituents of air are nitrogen, oxygen, carbon dioxide and argon. The percentage composition of constituents of air are as given below:

Name of Constituents	% Composition
Nitrogen gas	$78.1$%
Oxygen gas	$20.9$%
Carbon dioxide gas	$0.03$%
Argon	$0.9$%

Other components of air are water vapour and dust particles.