Thickness of atmosphere is:

Explanation

The layer of gases surrounding the earth is called atmosphere. It consists of various gases in different proportions i.e., N2 (78%), O2 (21%), Ar (0.9 %), CO2 (0.03 %) and trace amounts of H2, O3, CH4, CO, He, Ne, Kr and Xe. It also contains varying amounts of water vapours. Its thickness is about 1000 km above the surface of the earth and half of its mass is concentrated in the lower 5.6 km.