Our earth contains a great variety of gases, the most proportion is Nitrogen which is around 78% of all gases in the earth, while Oxygen is the second range at 20%. The rests include Hydrogen, Carbon dioxide and Ozone gases which occupy the atmosphere in different amounts according to the layers of atmosphere.

• The earth contains 4 atmosphere layers;
• 1. Troposphere is the layer reaching from the ground to 12 kilometers
• 2. Stratosphere is the source of ozone gas, this layer is found 12-50 kilometers above the ground.
• 3. Mesosphere begins 50 to 85 kilometers above the ground.
• 4. Thermosphere starts from about 85 kilometers upward.