# Explain why radio waves and gamma rays travel at the same speed in a vacuum but have very different frequencies.

> AQA GCSE Physics (8463) — 4.6.2 Electromagnetic waves · Explain · 4 marks

> Radio waves and gamma rays are both part of the electromagnetic spectrum, yet their frequencies differ enormously.

## Mark scheme (4 marks)

1. All electromagnetic waves travel at the same speed in a vacuum (the speed of light / 3 × 10⁸ m/s)
2. Because speed is constant, wavelength and frequency are inversely related (as wavelength decreases, frequency increases)
3. Gamma rays have a much shorter wavelength than radio waves
4. Therefore gamma rays have a much higher frequency than radio waves (and higher frequency means greater energy)

## Key terms

- [vacuum](https://www.gradenine.co.uk/glossary/vacuum)

## Related

- [Revision notes for AQA GCSE Physics (8463)](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-radio-waves-and-gamma-e98cafbe) · Published by Druglandscape Ltd.