Question

Carbon Dioxide is heavier than both,Oxygen and Nitrogen.Why does it not form a layer in the atmosphere?

Answer 1

Though carbon dioxide gas is heavier than oxygen and nitrogen, yet it does not form a layer by itself because being a gas, the rate of diffusion in carbon dioxide would be high. As a result its molecules would be distributed throughout the atmosphere and not just remain concentrated at one place. Also, the mass of each individual molecule is extremely small. Hence, these molecules would not be affected by the force of gravitation of the earth and therefore not form a layer by themselves.