Early volcanoes discharged different combinations of gases into the Earth's atmosphere creating rain, which cooled the planet and formed solid land masses, and every other element discovered presently.
energy from the sun,lightening,earths heat triggered chemical reaction for the early gases of the earth combined
They look at the mineral composition of the rocks. There are some minerals that can only form in the presence of oxygen.
What happened to all the water vapour in the early atmosphere
Carbon doixide
hot air .dude that is easy
There are smallamount of volcanoes. They emit so2 and co2 gases.
yes
oxygen
oxygen
nitrogen
no it wasn't
no
photosynthsis
photosynthesis
nitrogen
Photosynthesis by plants
Hydrogen and helium