# Explain why some materials are transparent to visible light but opaque to ultraviolet radiation.

> Eduqas GCSE Physics — 6.2 Interactions of electromagnetic radiation with matter · Explain · 4 marks

> Different materials interact differently with different parts of the electromagnetic spectrum. Glass, for example, allows visible light to pass through but blocks most ultraviolet radiation.

## Mark scheme (4 marks)

1. Transparent materials transmit visible light — photons pass through without being absorbed
2. The photons of ultraviolet radiation have higher frequency / more energy than visible light photons
3. The higher-energy UV photons are absorbed by the atoms / electrons in the material
4. Because UV is absorbed and does not pass through, the material appears opaque to UV

## Key terms

- [transparent](https://www.gradenine.co.uk/glossary/transparent)
- [opaque](https://www.gradenine.co.uk/glossary/opaque)
- [ultraviolet radiation](https://www.gradenine.co.uk/glossary/ultraviolet-radiation)

## 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/explain-why-some-materials-are-transparent-e04c1bef) · Published by Druglandscape Ltd.