# A photographer notices that some materials appear a different colour when viewed under ultraviolet (UV) light compared to visible light. Explain why ultraviolet radiation and visible light behave differently when interacting with these materials, and state one property that ultraviolet radiation and visible light share as members of the electromagnetic spectrum.

> OCR GCSE Physics A: Gateway Science (J249) — P4.2 The electromagnetic spectrum · Explain · 4 marks

> Ultraviolet radiation and visible light are both parts of the electromagnetic spectrum, but they have different frequencies and wavelengths.

## Mark scheme (4 marks)

1. Ultraviolet radiation has a higher frequency than visible light
2. Higher frequency means higher energy (per photon / wave), so UV interacts differently with materials
3. Both UV and visible light travel at the same speed in a vacuum / through air
4. Both UV and visible light are transverse waves (accept: both do not need a medium / can travel through a vacuum)

## Key terms

- [electromagnetic spectrum](https://www.gradenine.co.uk/glossary/electromagnetic-spectrum)
- [ultraviolet radiation](https://www.gradenine.co.uk/glossary/ultraviolet-radiation)
- [visible light](https://www.gradenine.co.uk/glossary/visible-light)

## Related

- [Revision notes for OCR GCSE Physics A: Gateway Science (J249)](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-photographer-notices-that-some-materials-9f125c37) · Published by Druglandscape Ltd.