Which gas found in today's atmosphere was virtually absent in the Hadean's and Archean's?
A) nitrogen
B) water vapor
C) oxygen
D) carbon dioxide

Question

Quizplus · Accepted Answer

Oxygen was virtually absent in the Hadean and Archean atmospheres, but it began to increase during the Proterozoic era due to the evolution of photosynthetic organisms. Nitrogen, water vapor, and carbon dioxide were all present in the early atmosphere.

Which Gas Found in Today's Atmosphere Was Virtually Absent in the Hadean's