Question

Many lab groups expected the rooms and hallways on the second floor to have the lowest relative humidity. Which reason below explains why this ended up being true?

(a) These locations tend to be warmer, and higher temperatures cause the relative humidity to drop.
(b) These locations are far away from sources of water.
(c) The rainstorm that occurred the day before the lab contributed to drier air on the second floor.
(d) These locations have lots of people. People lower the relative humidity when they breathe.

Answer 1

Option (a) is correct because warmer temperatures on the second floor can hold more water vapor, leading to lower relative humidity if the actual water vapor amount does not increase proportionately.

Step-by-step explanation:

The correct reason why the rooms and hallways on the second floor had the lowest relative humidity is explained by option (a): 'These locations tend to be warmer, and higher temperatures cause the relative humidity to drop'. This happens because relative humidity is a measure of how much water vapor is in the air compared to the maximum possible at a given temperature. As the temperature increases, the air can hold more water vapor, and if the actual amount of vapor does not increase proportionally, the relative humidity decreases. This is why hot air can dry items better, as it can hold more vapor.