Q540
In a volume of air near the earth's surface, ____ occupies 78 percent and ____ nearly 21 percent.
A.
Nitrogen, oxygen
AnswerB.
Hydrogen, oxygen
C.
Oxygen, hydrogen
D.
Nitrogen, water vapor
E.
Hydrogen, helium
Answer: Option A
Solution
Answer: Option A
Solution:
In a volume of air near the earth's surface, nitrogen occupies 78 percent and oxygen nearly 21 percent.