How did the original reducing atmosphere of primitive earth change ?

The atmosphere of primitive earth was

The atmosphere of primitive earth was

What was effect of oxygen on methane and ammonia found in the reducing atmosphere of primitive earth?

What was the effect of oxygen on methane and ammonia found in the reducing atmosphere of primitive earth?

Atmosphere of the primitive earth was characterised by:

How atmosphere covers the earth ?

What was the nature of atmosphere on the primitive earth?

Which gas was absent in the atmosphere of primitive earth ?

What was the nature of atmosphere in the primitive earth ?

What was the kind of atmosphere on the primitive earth?