Unit Review: The Atmosphere

Composition:

78% Nitrogen

21%Oxygen

.9% Argon

.03%CO2

Outgassing: gasses (CO2, SO2, H2O, N) were released from the interior of Earth

4.6 bya, Earth's atmosphere contained mainly CO2 and water vapor. It became the atmosphere it is today around 3.8 bya.

The 5 layers of the atmosphere are classified by:

-temp changes

-chemical composition

-density

Layers:

Troposphere- 0-11 km bottom layer, we live here, weather occurs here, temp decreases with altitude

Stratosphere- 11-50km

Mesosphere- 50-90km

Thermosphere- up to 500 km