The amount of water vapor in the air (by volume) usually does not exceed:
A) 100 percent.
B) 40 percent.
C) 4 percent.
D) 14 percent.
E) 28 percent.

Question

Quizplus · Accepted Answer

The amount of water vapor in the air (by volume) usually does not exceed 4 percent. This is because the air can only hold a certain amount of moisture at a given temperature, and this amount is expressed as a percentage of the maximum water vapor capacity of the air, which varies depending on temperature. The maximum capacity at a warm temperature is higher than at a cooler temperature, but even at the warmest temperatures, the maximum water vapor capacity of the air does not exceed 4 percent.

The Amount of Water Vapor in the Air (By Volume)