The formation of dew on the ground is an example of which specific thermal phenomenon in the water cycle?

Correct answer: Condensation when air reaches its dew point as the ground cools

The correct answer is B: condensation at the dew point. At night, the ground often loses heat and becomes cooler than the surrounding daytime surface. The thin layer of air touching the ground also cools. When this air reaches its dew point, it cannot hold all its water vapour as an invisible gas. The excess vapour changes into tiny liquid-water droplets on cool grass, leaves, soil, or other surfaces. This change is condensation, not evaporation, because gas becomes liquid. A is incorrect because evaporation changes liquid water into vapour. C is incorrect because direct ice-to-gas change is sublimation. D describes water entering soil, not droplets forming on a surface. Memory cue: dew means vapour deposits as liquid after cooling; frost is the related solid form.