The Breath of Life: Air
Air is a mixture of many gases like nitrogen, oxygen, carbon dioxide and water vapour.
Oxygen gas present in air is essential to living organisms for respiration. That is why air is called breath of life.
Air being a bad conductor of heat helps to maintain the moderate temperature on earth.
The air surrounding the earth is called the atmosphere. The atmosphere is divided into distinct layers- troposphere, stratosphere, mesosphere, thermosphere, exosphere, and ionosphere.
The air is corrosive in nature. The corrosion ability of air depends upon the amount of pollutant present in it. Air in the industrial area contains high levels of sulfur dioxide and nitrogen oxides. The air in the marine environment has traces of chloride salts. The air in rural areas has no harmful pollutants. The air in urban areas contains pollutants from the automobiles and industries.
Air plays a major role in the water cycle, weather cycle, and production of oxygen. Water is constantly circulated through the water cycle. Water vapour is the gaseous form of water which falls on earth as rain. Oxygen is produced by the trees through a process called photosynthesis. The trees take in carbon dioxide, process it, and release oxygen.
Carbon dioxide also absorbs and emits infrared radiations. Ozone is an effective absorber of ultraviolet radiations. The air is a bad conductor of heat, and it keeps the climate of the earth under control during the day. If there was no air, the temperature of the earth would have risen to a very high degree.
In the coastal regions, the air gets heated and rises up. As the air rises, low pressure is created, and the air from the sea moves inland. This movement of air causes wind. Air is the most important element for sustaining life on earth. If there is no air, the temperature of the earth will rise drastically and hamper the survival.