# Explain why nuclear fusion releases energy and describe the conditions needed for nuclear fusion to occur.

> AQA GCSE Physics (8463) — 4.4.4 Nuclear fission and fusion (Phys only) · Explain · 4 marks

## Mark scheme (4 marks)

1. Nuclear fusion involves two small/light nuclei joining to form a larger/heavier nucleus
2. Energy is released during the process of fusion
3. Very high temperatures are needed for fusion to occur
4. The high temperatures are needed so that nuclei have sufficient energy/speed to overcome the electrostatic/repulsive force between them and get close enough to fuse

## Key terms

- [nuclear fusion](https://www.gradenine.co.uk/glossary/nuclear-fusion)
- [energy](https://www.gradenine.co.uk/glossary/energy)

## Related

- [Revision notes for AQA GCSE Physics (8463)](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-nuclear-fusion-releases-energy-b022b435) · Published by Druglandscape Ltd.