Question

what happens to a moist air mass as it moves upward in the atmosphere?
its temperature remains the same.
it becomes warmer and forms clouds.
its temperature varies greatly.
it becomes cooler and forms clouds.

Explanation:

When a moist air mass moves upward in the atmosphere, it expands due to the decrease in pressure. As it expands, it cools (adiabatic cooling). When the air cools to its dew - point temperature, water vapor condenses to form clouds. Option A is incorrect because the temperature does not remain the same. Option B is wrong as it does not become warmer. Option C is incorrect as the temperature change is not highly variable in a random sense but follows a physical principle (adiabatic cooling).

Answer:

D. It becomes cooler and forms clouds.