Composition of Air
The air that we breathe is a mixture of many gases like oxygen, nitrogen, carbon dioxide, argon etc. The majority of the atmosphere is made up of nitrogen (78%) and oxygen (21%). The other gases that are present in small quantities are: Carbon dioxide (0.03%), Argon (0.93%) and Others ( helium, hydrogen, ozone). Tiny dust particles are also present in the air, apart from the above gases.
Nitrogen: It is the gas that is most abundant in the air. Plants need nitrogen to make protein. Plants cannot take the gaseous nitrogen from air. Some bacteria live in soil and in roots of some plants. These bacteria take the nitrogen form air and change it to a form so that plants can utilize nitrogen.
Oxygen: It is the second most plentiful gas in the air. Oxygen plays an important role for human beings, animals and plants in the following ways. Most of the living beings need oxygen for respiration. Green plants produce oxygen during photosynthesis.
The consumption of oxygen by human beings and animals is replenished by the production of the same by plants. Hence, the oxygen content in the air remains balanced. Indiscriminate felling of trees disturbs this balance.
Carbon dioxide: It is another important gas. Green plants need carbon dioxide to carry out photosynthesis. Most of the living beings release carbon dioxide during respiration.
Photosynthesis is a process used by plants and other organisms to convert the light energy, normally from the Sun, to chemical energy that can be later released to fuel the organisms’ activities.