Earth's Hadean atmosphere had far less of which gas,compared to now?
A) oxygen (O₂)
B) ozone (O₃)
C) methane
D) Archean

Question

Quizplus · Accepted Answer

During the Hadean Eon, around 4.6 to 4 billion years ago, the earth's atmosphere was mainly composed of gases like methane, ammonia, and water vapor. As the atmosphere evolved, it became richer in oxygen due to the emergence of photosynthetic organisms. Hence, the Hadean atmosphere had far less oxygen compared to the current atmosphere.

Earth's Hadean Atmosphere Had Far Less of Which Gas,compared to Now