Dew forms as moisture condensed from water vapor, typically on cooler objects near the ground.

• A. Fog
• B. Frost
• C. Dew
• D. Clouds

Answer: (C)

Dew is formed when water vapor condenses into liquid on cooler surfaces near the ground. After a clear night, surfaces such as grass or a car roof lose heat to the cold sky and their temperatures fall to the dew point of the surrounding air. When that happens, the water vapor in the air condenses into tiny liquid droplets on the surface, giving us dew in the morning. If the surface were cold enough to freeze, the water vapor would deposit as ice and you’d get frost instead of dew. Fog, by contrast, is a mist of tiny droplets suspended in the air near the ground, not liquid on a surface. Clouds form higher up in the atmosphere where rising air cools and moisture condenses in the air, not onto ground surfaces. So the description points to dew.