# When a sealed container of gas is heated at constant volume, its pressure increases. Explain why, in terms of the behaviour of the gas particles.

> Eduqas GCSE Physics — 2.6 Particle physics and using physics to investigate the universe · Explain · 4 marks

## Mark scheme (4 marks)

1. Heating the gas increases the temperature, which increases the average kinetic energy (and speed) of the gas particles.
2. The faster-moving particles collide with the walls of the container more frequently.
3. The particles also collide with the walls with greater force (harder).
4. Pressure is the perpendicular force per unit area on the container walls, so more frequent and harder collisions result in greater pressure.

## Key terms

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

## Related

- [Revision notes for Eduqas GCSE Physics](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/when-a-sealed-container-of-gas-cc0207b9) · Published by Druglandscape Ltd.