In order for organic molecules to have formed on the early Earth, what do we know could not have been present in the atmosphere in significant quantities?
A) oxygen (O₂)
B) nitrogen (N₂)
C) carbon dioxide (CO₂)
D) argon (Ar)

Question

Quizplus · Accepted Answer

Oxygen (O₂) could not have been present in the atmosphere in significant quantities during the early Earth because it was only generated by photosynthetic organisms much later in Earth's history.

Answer: B
 Nitrogen (N₂) was likely present in the early Earth's atmosphere and is not known to have prevented the formation of organic molecules.

Answer: C
 Carbon dioxide (CO₂) was likely present in the early Earth's atmosphere and was thought to have played a role in the formation of organic molecules.

Answer: D
 Argon (Ar) is an inert gas and would not have had much of an impact on the formation of organic molecules on the early Earth.

In Order for Organic Molecules to Have Formed on the Early