Under which condition is evaporation from a water surface most likely to be low?

Correct answer: Cool, saturated, calm air

The correct answer is B: cool, saturated, calm air. Evaporation is the change of liquid water into water vapour. It becomes faster when temperature is high, the surrounding air is dry, and wind removes vapour from the surface. In cool air, water molecules have less energy to escape. Saturated air is already holding nearly the maximum water vapour possible at that temperature, so it has little capacity to accept more. Calm air also allows moist air to remain above the surface. Therefore all three conditions in B oppose rapid evaporation. A has warmth, dryness, and strong wind, so it promotes evaporation. C has high temperature and dry air, which also promote it, even though wind is not mentioned. D has strong wind and low humidity, both of which strongly increase evaporation. Memory cue: heat, dryness, and moving air increase evaporation; cool, humid, and still air decrease it.