Air surrounding us is a mixture of several gases . Let's see the gases present in air 

Nitrogen comprises 78 per cent of the Earth's atmosphere . Plants and animals cannot utilise nitrogen directly from the atmosphere 

Earth atmosphere is composed of 21 per cent oxygen . It is one of the most important components of air because it is needed by living organisms 

The 1 per cent is of carbon dioxide , argon , water vapour , and other gases used by plants or the gases used for packing food ( like used in chips )