# A geologist discovers a rock sample that is radioactive. Tests show the sample emits all three types of nuclear radiation: alpha, beta, and gamma. Explain why gamma radiation is the most difficult type of radiation to shield against.

> OCR GCSE Physics A: Gateway Science (J249) — P4.3 Radioactive emissions · Explain · 4 marks

> A geologist discovers a rock sample that is radioactive. Tests show the sample emits all three types of nuclear radiation: alpha, beta, and gamma.

## Mark scheme (4 marks)

1. Gamma radiation has very high penetrating power
2. Gamma radiation is an electromagnetic wave / has no mass and no charge
3. Because gamma radiation has no charge it interacts very weakly with matter / ionises poorly
4. Several centimetres of lead or metres of concrete are needed to significantly reduce gamma radiation

## Key terms

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

## Related

- [Revision notes for OCR GCSE Physics A: Gateway Science (J249)](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-geologist-discovers-a-rock-sample-9185d9fa) · Published by Druglandscape Ltd.