Where did it come from?

This task is about condensation.

Condensation occurs when gas turns into a liquid.

condensation on the window

The next two questions explore your understanding of the change of state from a gas to a liquid. 

Question

Mark was looking closely at his teeth in the bathroom mirror. The mirror went misty. What is the best explanation for this?

    • Mark's breath contains carbon dioxide which misted up the mirror.

    • Steam from water in the wash basin misted up the mirror.

    • Water vapour in Mark's breath was forming tiny droplets on the cold glass.

    • The cold morning air was condensing on the warmer surface of the mirror.

Question

One morning when he walked across the park to school, Daniel's shoes got wet from the dew on the grass. Which best explains where dew comes from?

    • From the damp soil under the grass.

    • It is made by the blades of the grass during the night.

    • From the clouds which were present overnight.

    • From the moisture in the air around the grass.