# A hospital uses radioactive isotopes in two ways: to image internal organs and to sterilise surgical equipment. Explain why different types of nuclear radiation are chosen for each of these two uses, referring to the penetrating power and ionising ability of the radiation in each case.

> Eduqas A-Level Physics — 6.1 Radioactivity · Explain · 5 marks

> Radioactive isotopes emit alpha particles, beta particles or gamma rays. Each type of radiation has different penetrating power and ionising ability.

## Mark scheme (5 marks)

1. Gamma radiation is used for sterilising surgical equipment (or medical imaging)
2. Gamma radiation has high penetrating power, so it can pass through packaging / the body to reach equipment or organs
3. Gamma radiation has low ionising ability, reducing damage to surrounding cells / tissue during imaging
4. Alpha radiation (or beta) would not be suitable for imaging / sterilisation because it cannot penetrate far enough / is stopped by skin or thin materials
5. Alpha radiation is the most strongly ionising, so it would cause the greatest cell damage / mutations if used inside the body

## Key terms

- [penetrating power](https://www.gradenine.co.uk/glossary/penetrating-power)
- [ionising ability](https://www.gradenine.co.uk/glossary/ionising-ability)
- [nuclear radiation](https://www.gradenine.co.uk/glossary/nuclear-radiation)

## 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-hospital-uses-radioactive-isotopes-in-7eea8d52) · Published by Druglandscape Ltd.