Nitrogen makes up about 78.1 percent of the atmosphere, oxygen 20.9 percent, and Argon 0.93 percent. The other gases that can be found in the Earth's atmosphere are neon, helium, methane, krypton, and hydrogen.
It is divided into layers, the lowest of which is the troposphere (6 to 20 km), then the stratosphere (20 to 50 km), mesosphere (50 to 85 km), thermosphere (85 to 690 km), and exosphere (690 to 10,000 km).
