Which highly reactive gas was probably absent from the Earth's primitive atmosphere?
A) methane
B) carbon dioxide
C) oxygen
D) water vapor

Question

Quizplus · Accepted Answer

Oxygen is the highly reactive gas that was probably absent from the Earth's primitive atmosphere. It was likely introduced through photosynthesis by early life forms. The other gases listed were all likely present in the primitive atmosphere.

Which Highly Reactive Gas Was Probably Absent from the Earth's