Waves and the electromagnetic spectrum

Ages 13 to 17 Read alone · about 40 minutes

Read together

A wave carries energy without carrying matter. Waves have a wavelength, a frequency and an amplitude.

Visible light is a small part of the electromagnetic spectrum, which also includes radio waves, microwaves, X-rays and more.

Do it

1. Shake a rope or slinky to make waves. Change the speed and see the wavelength change.
2. Use a glass of water and a torch to split light into colours on a wall (a prism effect).
3. List where you meet each part of the spectrum: radio, Wi-Fi, microwaves, light, UV, X-rays.
4. Note why sunscreen protects from UV.

Talk about it

• What changes between radio waves and X-rays?
• Why can we see only some waves?

For the grown-up

The electromagnetic spectrum ranges from radio waves to gamma rays. Never look at the Sun or a laser directly. Keep torches from eyes.

Mark as done

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Where this comes from

• NGSS Lead States, Next Generation Science Standards: For States, By States (National Academies Press, 2013), performance expectation MS-PS4-1 (waves: amplitude and energy)
• NASA, Science Mission Directorate, pages on the electromagnetic spectrum

Written with AI assistance and checked against the sources listed. Please read it before sharing it with a child.