# A hospital uses a radioactive source to treat a tumour inside a patient's body. The source emits gamma radiation and has a long half-life. Explain why gamma radiation and a long half-life are both suitable properties for this medical use.

> Eduqas GCSE Physics — 2.4 The atom, the nucleus and radioactivity · Explain · 4 marks

## Mark scheme (4 marks)

1. Gamma radiation is highly penetrating, so it can pass through body tissue to reach the tumour inside the patient
2. Alpha and beta radiation would be absorbed by surrounding tissue before reaching the tumour, so only gamma is suitable
3. A long half-life means the source remains active / does not decay significantly during the course of treatment
4. A long half-life means the dose delivered to the patient is consistent / predictable over the treatment period

## Key terms

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

## Related

- [Revision notes for Eduqas GCSE 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-a-radioactive-source-be59f417) · Published by Druglandscape Ltd.