Earth's Atmosphere

The atmosphere is a layer of gases that surround the Earth. It consists primarily of nitrogen (78%) and oxygen (21%) but also contains argon (0.9%), carbon dioxide (0.03%), water vapor (from4%to nearly none at all) and ozone.
The atmosphere also has solid particles such as smoke, pollen,dust,and meteor debris.
The atmosphere is divided horizontally into four layers on the basis of temperature: troposphere, stratosphere, mesosphere, thermosphere.