# Explain the difference between nuclear fission and nuclear fusion, and state one similarity between the two processes.

> WJEC GCSE Physics (Wales) — 2.9 Nuclear decay and nuclear energy · Explain · 4 marks

## Mark scheme (4 marks)

1. Nuclear fission is the splitting of a large/heavy nucleus into two smaller nuclei (fragments)
2. Nuclear fusion is the joining/combining of two small/light nuclei to form a larger nucleus
3. Both processes release (large amounts of) energy
4. Both processes involve a change in the nucleus / both are nuclear reactions / both involve a change in nuclear mass

## Key terms

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

## Related

- [Revision notes for WJEC GCSE Physics (Wales)](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-the-difference-between-nuclear-fission-faac1b8b) · Published by Druglandscape Ltd.