Answer:
The atmosphere refers to the gaseous envelope of earth. It is comprised of various gases with variable composition. The atmosphere of the earth id divided into different layer, namely-
1) Troposphere- It is the layer that is in contact with the surface of the earth. It covers a height up to about 10 km from the ground surface. In this layer, the temperature decreases with the altitude and most of the weather phenomenon takes place here.
2) Stratosphere- This layer extends from 10 to 50 km approximately from the ground surface. in this layer the temperature increases with the altitude. It is due to presence of ozone in this layer that traps the incoming solar radiation.
3) Mesosphere- This layer is above the stratosphere and it extends from about 50 to 80 km above the earth's surface. In this layer, the temperature again decreases with height. here, the temperature drops up to -90°C.
4) Thermosphere- This layer extends from a height of 80 to 500 km approximately above the surface of the earth. In this layer, the temperature again rises with the increasing altitude.
5) Exosphere- This is the extreme outer layer of the atmosphere. It ranges from about 500 to 10,000 km above the earth's surface. The air in this region is comprised of hydrogen and helium.