Question

which is an example of condensation?
a. three inches of rain fall in one hour.
b. a layer of water appears on the outside of a cup of ice water.
c. a foot of snow falls in midwinter.
d. on a hot day, water on the sidewalk quickly disappears.

Explanation:

To determine the example of condensation, we analyze each option:

• Option A: Rainfall is precipitation (water falling from clouds), not condensation. Condensation is the change of water vapor to liquid, while precipitation is liquid water falling.
• Option B: The layer of water on the outside of a cup of ice water forms because water vapor in the air (which is gaseous) comes into contact with the cold surface of the cup. The cold surface cools the water vapor, causing it to change from a gas to a liquid (condensation). This is the process of condensation.
• Option C: Snowfall is a form of precipitation (solid water falling from clouds), not condensation. Snow forms in clouds through processes like deposition (water vapor changing directly to ice) or freezing of liquid water droplets, but the falling snow is precipitation.
• Option D: Water on the sidewalk disappearing on a hot day is evaporation (liquid water changing to water vapor), the opposite of condensation.

Answer:

B. A layer of water appears on the outside of a cup of ice water.