Hydrogen and Helium
The main gases in Earth's atmosphere are nitrogen, followed by oxygen.
Hydrogen and helium are the two main gases in the Universe.
There are not two gases in the layer but one. Ozone is the only gas present in the ozone layer.
canada
Two main gases exchange in the lungs: oxygen and carbon dioxide.
Hydrogen and helium
usually Argon or Nitrogen
carbon dioxide and nitrogen
helium and hydroen
amonia, hydrogen,
Oxygen Carbon dioxide
The two main atmospheric gases are nitrogen and oxygen. The approximate percentage for nitrogen is 78% and oxygen's approximate percentage is 21%.