# Explain why X-rays are used to produce images of bones inside the human body, but infrared radiation is not suitable for this purpose. Your answer should refer to the properties of both types of electromagnetic radiation.

> Cambridge International IGCSE Physics (0625) — 3.3 Electromagnetic spectrum · Explain · 4 marks

## Mark scheme (4 marks)

1. X-rays have a high frequency / short wavelength (compared to infrared)
2. X-rays can penetrate soft tissue / pass through the body but are absorbed by / cannot pass through dense bone
3. Infrared radiation is absorbed by / cannot penetrate soft tissue / skin
4. Therefore infrared cannot reach the bone / produce an image of internal bone structure

## Key terms

- [X-rays](https://www.gradenine.co.uk/glossary/x-rays)
- [infrared](https://www.gradenine.co.uk/glossary/infrared)

## Related

- [Revision notes for Cambridge International IGCSE Physics (0625)](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/explain-why-x-rays-are-used-to-0eaddba1) · Published by Druglandscape Ltd.