What is a composition air

Air is a mixture of gases, water vapour and dust particles. Some of the gases; present in air; are discussed below.

Nitrogen: Nitrogen is the largest component of air. Nitrogen makes up 79% of air around us. Nitrogen is used by plants to make protein. Plants cannot take nitrogen directly from the air. Some nitrogen fixing bacteria live in soil. They help in nitrogen fixation in soil. Thus, plants are able to take nitrogenous compounds from the soil.

Oxygen: Oxygen is the second largest component of air. Oxygen makes up 21% of the air around us. Oxygen is used by living beings for respiration. After respiration, the living beings produce carbon dioxide.

Carbon dioxide: The remaining 1% of air is composed of carbon dioxide, many other gases, water vapour and dust particles. Carbon dioxide is also important for living beings. Plant need carbon dioxide to make food during photosynthesis. During photosynthesis, plants take in carbon dioxide and release oxygen. Thus, green plants help in maintaining the balance of carbon dioxide and oxygen in atmosphere.