# Explain why alpha radiation is more ionising than gamma radiation.

> WJEC GCSE Physics (Wales) — 2.7 Types of radiation · Explain · 4 marks

> Radioactive sources can emit different types of radiation. These types of radiation differ in their ability to ionise atoms in the materials they pass through.

## Mark scheme (4 marks)

1. Alpha particles are relatively large / have a large mass compared to gamma radiation
2. Alpha particles carry a charge of +2 / are strongly charged, so they interact strongly with electrons in surrounding atoms
3. Alpha particles move relatively slowly / lose energy quickly as they travel through matter, causing many ionising collisions per unit distance
4. Gamma radiation has no charge and no mass, so it interacts very little with atoms / passes through matter without causing much ionisation

## Key terms

- [alpha radiation](https://www.gradenine.co.uk/glossary/alpha-radiation)
- [gamma radiation](https://www.gradenine.co.uk/glossary/gamma-radiation)
- [ionising](https://www.gradenine.co.uk/glossary/ionising)

## 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-why-alpha-radiation-is-more-97f5e4b2) · Published by Druglandscape Ltd.