Describe air and it's composition

Air is made up of 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and other gases in meager amounts. Water vapor is also a constituent of air in varying amounts along with dust particles. The molar mass of dry air or air with no/low quantity of water vapor in it is 28.97g/mol.

Air is a gaseous substance that is composed primarily of nitrogen, oxygen and argon. The air in the atmosphere that surrounds the Earth is approximately 78 percent nitrogen, 21 percent oxygen and 1 percent argon, with the remainder made up of various other gases including neon, helium and hydrogen.