What is the origin of the atmosphere?

Question

im studying for a science test, and i need to know what the origin of the atmosphere is, can anyone help pleaseeee? it would help a lot!

Answer 1

Probably from capture from space and compression by a relatively large-sized planet and outgassing of the earth's interior through time formed the "primorda" atmosphere. Plants supposedly became able to convert CO2 in the air with water and produce oxygen. The oxygen content built up until it was tied up in carbonate mineral or was used by evolving animal life forms. This leaves a lot of nitrogen floating around, which would probably would have been produced from plant matter utilizing nitrate
(NO3-) as nutrient.