Question

After nitrogen and oxygen and ignoring water vapor concentration, the most abundant gas in earth's atmosphere is:

1) argon
2) carbon dioxide
3) hydrogen
4) methane

Answer 1

1) argon

Argon is the third most abundant gas in Earth's atmosphere after nitrogen and oxygen, making up about 0.93% of the atmosphere.

Step-by-step explanation:

After nitrogen (78%) and oxygen (21%), and ignoring water vapor concentration, the most abundant gas in Earth's atmosphere is argon.

Argon makes up about 0.93% of the atmosphere. Carbon dioxide, although also a significant component, makes up about 0.04%. Other gases like hydrogen and methane are present in even smaller amounts.

Therefore, argon is the third most abundant gas in the atmosphere when water vapor is not considered.