Condensation

water cycle · weather · science

Gas turns to liquid. Condensation happens when water vapor, which is invisible gas floating in the air, cools down enough to become liquid water droplets. This is the opposite of evaporation, where liquid water turns into gas.

Your mirror gets foggy. When you take a hot shower, the warm air full of water vapor hits your cool bathroom mirror. The water vapor condenses on the cold surface and creates that foggy layer you can draw on.

Clouds are condensation. High up in the sky where it's cold, water vapor condenses around tiny bits of dust and salt to form clouds. Billions of tiny water droplets stuck together make the fluffy shapes you see.

Part of the water cycle. Condensation is a key step in Earth's water cycle. Water evaporates from oceans and lakes, rises into the atmosphere, then condenses back into liquid when it gets cold enough.

Frost is frozen condensation. When water vapor condenses directly into ice instead of liquid water (usually on very cold mornings), it's called deposition, and it creates frosty patterns on grass and windows.