The Early Atmosphere of Earth Consisted Mainly Of

Question

The early atmosphere of Earth consisted mainly of
A) hydrogen, oxygen, and carbon dioxide.
B) oxygen, water vapor, and carbon monoxide.
C) water vapor, nitrogen, and carbon dioxide.
D) hydrogen, carbon monoxide, and nitrogen.
E) water vapor, hydrogen, and carbon dioxide.

Accepted Answer

The early atmosphere of Earth is believed to have consisted mainly of water vapor, nitrogen, and carbon dioxide. This is based on studies of ancient rocks and fossils, as well as the analysis of gases released by volcanic eruptions. Oxygen was not a significant part of the atmosphere until later, when photosynthetic organisms began producing it as a byproduct of their metabolic processes.