# Explain why evaporation of a liquid causes the remaining liquid to cool, using ideas about particles and energy.

> IB DP Chemistry Standard Level (2023 syllabus) — S1.1 Introduction to the particulate nature of matter · Explain · 4 marks

## Mark scheme (4 marks)

1. Particles in a liquid have a range (distribution) of kinetic energies.
2. Only the particles with the highest kinetic energies have sufficient energy to overcome intermolecular forces and escape from the surface.
3. When these high-energy particles leave, the average kinetic energy of the remaining particles decreases.
4. Since temperature is proportional to average kinetic energy of the particles, the temperature of the remaining liquid falls.

## Key terms

- [evaporation](https://www.gradenine.co.uk/glossary/evaporation)

## Related

- [Revision notes for IB DP Chemistry Standard Level (2023 syllabus)](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/explain-why-evaporation-of-a-liquid-7dbf3093) · Published by Druglandscape Ltd.