# A hospital uses gamma radiation from a radioactive source to treat a patient with a tumour. Explain why gamma radiation is chosen for this treatment and describe one hazard associated with this use of radiation, linking your answer to the properties of gamma radiation and the concept of half-life.

> OCR A-Level Physics B: Advancing Physics (H557) — 6.1 Capacitors · Explain · 5 marks

> Gamma-emitting radioactive isotopes are used in cancer treatment to target and destroy cancerous cells inside the body. The half-life of the isotope chosen, and the penetrating power of the radiation it emits, are both important factors in deciding whether an isotope is suitable.

## Mark scheme (5 marks)

1. Gamma radiation has the greatest penetrating power (of the three types of nuclear radiation)
2. Gamma radiation can therefore reach the cancerous cells deep inside the body without being absorbed by surrounding tissue
3. The gamma radiation transfers energy to the cancerous cells, killing them
4. Healthy cells surrounding the tumour may also be irradiated and destroyed, causing harmful side effects
5. An isotope with a short half-life is preferable because it decays quickly, reducing the long-term radiation dose to the patient

## Key terms

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

## Related

- [Revision notes for OCR A-Level Physics B: Advancing Physics (H557)](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-gamma-radiation-from-9fa8434f) · Published by Druglandscape Ltd.