Air is a mixture of several gases, mainly containing nitrogen, oxygen, carbon dioxide and small amounts of argon, helium, neon, hydrogen, etc. There is also some amount of dust, smoke and water content in the air, the percentage of which varies according to the environment.
Existing gases in the air are very important for our life in one form or the other.
Nitrogen gas is 78% of the total volume of the Earth's air. Nitrogen is an odorless and tasteless gas. It is neither flammable nor helpful in combustion.
About 21 percent of the total volume of air is of oxygen. Oxygen is also called Prana-Vayu. Without this, we cannot live. Pure oxygen is strong to smell. Nitrogen present in air reduces its sharpness.
All plants and animals require oxygen for respiration. When we breathe, we take in oxygen from the air and take out carbon dioxide.
Oxygen itself is not flammable but is helpful for flammation. The more oxygen the burning fuel gets, the faster it burns.
Oxygen is used for artificial respiration. Climbers, sea divers and astronauts also carry oxygen cylinders to breathe. Hospitals have oxygen cylinders. The mere amount of oxygen dissolved in water is not enough for our breath, although it is sufficient for living beings in water.
Carbon dioxide is found in very small amounts in the air, yet it is a very important component of air. Carbon-dioxide is produced in the respiration and fuel burning process of plants and animals. It is used in the process of producing food by green plants.
Carbon dioxide in the air also helps maintain a certain average global temperature. It is not helpful in combustion. It is a flame retardant gas.
4. Other gases
Other gases found in air are also very useful for us. For example, ozone prevents ultraviolet rays from the sun reaching the earth and thus protects us from their side effects.
5. Water Vapor
Water vapor is also found in the air which comes into the air when the sun rays evaporate from the earth's reservoirs.