# A technician is storing three different radioactive sources in a laboratory. One source emits alpha radiation, one emits beta radiation, and one emits gamma radiation. Describe the penetrating power of each type of radiation and state what material is needed to stop each one.

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

> Radioactive sources are used in many industrial and medical applications. Safe storage and handling of these sources requires an understanding of their penetrating power.

## Mark scheme (4 marks)

1. Alpha radiation has the least penetrating power / is stopped by a few centimetres of air or a thin sheet of paper
2. Beta radiation has intermediate penetrating power / is stopped by a few millimetres of aluminium (or equivalent thin metal sheet)
3. Gamma radiation has the greatest penetrating power
4. Gamma radiation is only partially absorbed / its intensity is reduced by thick lead or thick concrete

## Key terms

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

## Related

- [Revision notes for OCR GCSE Physics A: Gateway Science (J249)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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-technician-is-storing-three-different-7b90b45a) · Published by Druglandscape Ltd.