Question

question 17 how does humidity affect air pressure? humidity increases air pressure by adding more air molecules. humidity decreases air pressure because water vapor is less dense than dry air. humidity does not affect air pressure. humidity increases air pressure by making the air heavier.

Explanation:

Water vapor in humid air is less dense than the nitrogen and oxygen - rich dry air. When humidity increases, the proportion of water vapor in the air increases. Since water vapor is less dense, the overall density of the air decreases. According to the relationship between air density and air pressure (pressure is related to the weight and density of air), lower - density air exerts less pressure. So humidity decreases air pressure.

Answer:

Humidity decreases air pressure because water vapor is less dense than dry air.