Electromagnetic Spectrum

What this unit covers

The resources follow the spectrum from one end to the other. There are separate mind maps for Radiowaves, Microwaves, Infrared, Visible light, Ultraviolet Rays, Gamma rays and several on X-rays. Other maps look at the nature of waves, uses, benefits and risks, and satellite communication.

Where to start

Begin with the mind map called The Electromagnetic Spectrum. It covers the discovery of waves, including Isaac Newton and the visible spectrum, and defines the visible spectrum as the range of light waves the human eye can see. Next, open Nat 5 Physics Waves and Radiation, which links the spectrum to wave types, light and nuclear radiation. It notes that all waves transfer energy and that longitudinal waves vibrate in the same direction as the wave travels.

Going into detail

Once you have the overview, pick one wave type at a time.

• The RADIO WAVES map explains that long radio waves diffract, bend round hills and houses, and curve around the Earth.
• The microwaves map looks at satellite communication and why signals must pass easily through the watery atmosphere.
• The X-Rays map notes their high frequency, very short wavelength and effect on photographic film.

Using quizzes and maps together

Read a map, close it, then test yourself. The Waves and Radiation Quiz asks about frequency, diffraction and background radiation. The Color and Light Test asks what the source of electromagnetic waves is and how a vibrating electron makes a wave. The P2 Quiz covers sources of light and the speed of light through a vacuum. Any question you miss tells you which map to reread. Flashcard decks such as Electromagnetic Spectrum and EM Spectrum and Properties are good for quick recall of order and uses.

Where it sits

This unit belongs to the strand Waves, Sound and Light in Physics. Teachers can use the maps as ready-made starters, and students can pick a quiz to check what they know, then build their own versions.