nitrogen
oxygen
oxygen
Methane gas
ozone
ozone
oxygen
Carbon dioxide
Carbon dioxide used to make up most of Earth's early atmosphere.
gas-gas
He thought that the early Earth's atmosphere contained ammonia, NH3; hydrogen gas, H2; water vapor, H2o; and compounds made of hydrogen and carbon, such as, CH4.
The Gas Giants have a deep gas atmosphere and earth have a not so deep atmosphere
Oxygen was the least plentiful gas in Earth's early atmosphere. The atmosphere primarily consisted of carbon dioxide, water vapor, nitrogen, and small amounts of other gases. Oxygen levels rose significantly over time due to the process of photosynthesis by early life forms.