The table summarises the main types of electromagnetic radiation, and a typical use for each of them.
Wavelength |
Type of electromagnetic |
Typical use |
Frequency |
Shortest |
gamma rays | killing cancer cells | Highest |
| X-rays | medical images of fractured bones | ||
| ultraviolet light | sunbeds; detecting forged bank notes | ||
 |
visible light | seeing; iris recognition |  |
| infrared light | optical fibre communication | ||
| microwaves | cooking; monitoring rainfall | ||
Longest |
radio waves | television signals | Lowest |
All types of electromagnetic radiation:
- are transverse waves
- travel at the same speed in a vacuum (empty space)
The speed of electromagnetic radiation in a vacuum is very nearly three hundred million metres per second (not far off a million times faster than sound, which is why you see a flash of lightning before you hear the thunder).
Photons
A beam of electromagnetic radiation delivers energy in “packets” called photons. The different types of radiation listed in the table above have been arranged in order of the decreasing amount of energy delivered by each photon.
[ This page has been adapted from www.bbc.co.uk/schools/gcsebitesize/science
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