# A student takes a warm drink from the fridge. The drink is in a thin glass cup. The student notices that the outside surface of the glass quickly becomes wet, even though no liquid has been spilled. Explain why the outside of the glass becomes wet.

> Eduqas A-Level Physics — 3.4 Thermal physics · Explain · 5 marks

## Mark scheme (5 marks)

1. The glass is cold / the outside surface of the glass is at a lower temperature than the surrounding air
2. Water vapour is present in the air / the air contains water vapour (moisture)
3. Water vapour in the air loses thermal energy / cools down when it contacts the cold surface
4. The water vapour condenses / changes state from gas to liquid on the surface of the glass
5. This forms liquid water (droplets) on the outside of the glass

## Related

- [Revision notes for Eduqas A-Level Physics](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-takes-a-warm-drink-b730a10b) · Published by Druglandscape Ltd.