# A radioactive nucleus undergoes beta decay. Explain what happens inside the nucleus during beta decay and describe the properties of the beta particle that is emitted.

> Eduqas A-Level Physics — 3.5 Nuclear decay · Explain · 5 marks

## Mark scheme (5 marks)

1. A neutron changes into a proton (inside the nucleus)
2. The beta particle is an electron (emitted from the nucleus)
3. The beta particle has a negative charge
4. Beta particles have a range of a few metres in air (or are stopped by a few mm of aluminium)
5. The proton number (atomic number) of the nucleus increases by one (after beta decay)

## Key terms

- [beta decay](https://www.gradenine.co.uk/glossary/beta-decay)
- [beta particle](https://www.gradenine.co.uk/glossary/beta-particle)

## 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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-radioactive-nucleus-undergoes-beta-decay-9aa3ac50) · Published by Druglandscape Ltd.