Today is rung 3 of 5 on this topic
Waves and the electromagnetic spectrum
Can do: Relates wavelength, frequency and energy, and places everyday technologies on the spectrum.
Why it matters
It explains wifi, microwaves, X-rays, sunburn and phone signals — a single model behind a dozen daily things.
What it looks like when it's wobbly
Treats radio, light and X-rays as unrelated phenomena rather than one spectrum.
⏱️ Two-minute check
"Why does UV damage skin but radio doesn't, when both are electromagnetic?"
Solid looks like: Higher frequency means higher energy per photon.
The full activity for this topic · 25 minutes
Map the Spectrum in Your House
- 1Draw the spectrum as a line from radio to gamma.
- 2Place every device you can find: radio, wifi, microwave, remote control, lamp, sunlamp, X-ray at the dentist.
- 3Split white light with a prism or a CD and locate visible light on the line.
- 4Test the TV remote through a phone camera — the camera sees infrared, your eye doesn't.
- 5Explain sunscreen, and why microwave doors have a mesh.
If it's too hard
Place five devices on the line.
If it's too easy
Calculate frequency from wavelength using the speed of light.
Say this
"Same family, different energy. Which end of the line does that device sit on, and why?"