Question

In winter, what causes mist to form on a mirror or metal surface when we blow air on to it?

• A. The cool and moist air from our lungs meets the hot air of atmosphere
• B. The hot and dry air from our lungs meets the cool air of atmosphere
• C. The dry air from our lungs meets the hot air of atmosphere
• D. The warm and wet air from our lungs meets the cool air of atmosphere

Answer 1

The correct option is D

The warm and wet air from our lungs meets the cool air of atmosphere

When we exhale, the warm and wet air from our lungs meets the cold air of the atmosphere. As a result, the water vapours in the exhaled air condense into mist.