As air warms, what happens to its ability to hold water vapor?

As air warms, its ability to hold water vapor increases. This is due to the fact that warmer air can accommodate more moisture, which is a fundamental principle of thermodynamics. The relationship between temperature and humidity is governed by the fact that molecules in warmer air move more energetically, allowing for greater capacity to hold water vapor.

As the temperature rises, the kinetic energy of water molecules increases, making it possible for more water in vapor form to exist in the air without condensing into liquid. This is the reason why warm air is often associated with higher humidity levels. Thus, the correct choice reflects this essential understanding of how temperature affects the moisture-carrying capacity of air.