Question

most of the earths air mass is found in the atmospheric layer closest to the earths surface.
identify the gas that is most abundant in this region, which comprises 78% of the air.
choose 1 answer:
a carbon dioxide
b water vapor
c nitrogen
d oxygen

Explanation:

The troposphere (the layer closest to Earth's surface) has air composition where nitrogen makes up about 78%, oxygen about 21%, and small amounts of other gases like carbon dioxide and variable water vapor.

Answer:

C. nitrogen