Why a cold glass gets wet
Cold water goes into a steel glass. Minutes later, the outside is wet. Where did that water come from?
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Step 1 of 4
- A cold glass sits on the table.
- Vapour in the air comes near it.
- It cools and turns to liquid.
- Drops form outside. They come from the air.
The rule
The water came from the air around the glass.
Condensation is vapour turning back into liquid.
The air always holds some invisible vapour. On a cold surface, the vapour cools into tiny drops.
A humid day has damp air with more vapour. So a cold glass gets wet faster.