1. Introduction to air and its composition

Humans breathe in oxygen (\(O_2\)) and breathe out carbon dioxide (\(CO_2\)). Whereas plants use carbon dioxide for photosynthesis and release oxygen into the atmosphere.

 

  

 

Note: The process of bringing oxygen to our body by lungs is called inspiration or inhalation. Expiration or exhalation, on the other hand, is the process of sending carbon dioxide out through the lungs.

 

  

Air is composed of nitrogen (\(N_2\)), oxygen (\(O_2\)), argon (\(Ar\)), carbon dioxide (\(CO_2\)) and a small amount of other gases.

 

  

  

 

Humans are cutting the trees for their needs, so the level of carbon dioxide is increasing in the atmosphere. This is the reason for the rising temperature in the atmosphere.

 

Industries and vehicles release carbon monoxide (\(CO\)), sulphur dioxide (\(SO_2\)) and nitrogen oxides (\(NO_x\)) into the atmosphere. These air pollutants react with water, oxygen and other substances to produce airborne sulphuric acid (\(H_2SO_4\)) and nitric acid (\(HNO_3\)). This result in global warming, acid rain and the greenhouse effect.