Oxygen
Carbon dioxide
The two main gases found in the troposphere are nitrogen (about 78%) and oxygen (about 21%). These gases make up the majority of the Earth's atmosphere and are essential for supporting life.
The main gases in Earth's atmosphere are nitrogen, followed by oxygen.
Nitrogen (which makes up about 78% of the atmosphere) and Oxygen (about 21%)
Hydrogen and Helium
Hydrogen and helium are the two main gases in the Universe.
Nitrogen and Oxygen are the two main constituents of air.
The two main greenhouse gases that help keep the Earth's atmosphere warm and livable are carbon dioxide (CO2) and water vapor (H2O). These gases trap heat from the sun, which helps maintain a stable climate for supporting life on Earth.
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