# Explain, using kinetic theory, what happens to the particles in a gas when the gas is heated at constant volume, and why this causes the pressure of the gas to increase.

> Eduqas A-Level Physics — 3.3 Kinetic theory · Explain · 5 marks

## Mark scheme (5 marks)

1. Heating gives the particles more energy (internal/kinetic energy)
2. The particles move faster / have greater speed
3. Particles collide with the walls of the container more frequently
4. Each collision exerts a greater force on the walls (particles hit harder)
5. More frequent and harder collisions increase the overall force on the walls, so pressure increases

## Key terms

- [kinetic theory](https://www.gradenine.co.uk/glossary/kinetic-theory)
- [pressure](https://www.gradenine.co.uk/glossary/pressure)
- [particles](https://www.gradenine.co.uk/glossary/particles)

## 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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-using-kinetic-theory-what-happens-85d4c340) · Published by Druglandscape Ltd.