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EM spectrum
Beginner
Radio, microwave, infrared, visible, UV, X-ray, gamma.
Ordered by wavelength: radio (>1 m), microwave, infrared, visible (400–700 nm), ultraviolet, X-ray, gamma (<10 pm). Same nature, different frequency and photon energy.
A visible photon has about 2 eV.
Wavelength decreases as energy rises.
In more detail
The electromagnetic spectrum covers all frequencies of electromagnetic waves, from long radio waves through microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays. Their behaviour and uses differ with frequency.
Real-world uses
- Radio and TV use the long-wavelength end of the spectrum.
- Medicine uses X-rays and gamma rays for imaging and treatment.
- Engineers and scientists use the electromagnetic spectrum to choose the right wavelength for communication, imaging and medicine.
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Frequently asked questions
Are all these waves the same?
Yes, they are all electromagnetic waves, differing only in frequency and wavelength.
Which is most energetic?
Gamma rays, which have the highest frequency and photon energy.
What is the difference between a radio wave and an X-ray?
Both are electromagnetic waves, but radio waves have much longer wavelengths and lower energy than X-rays.
Related topics in AC Circuits & EM Waves
Poynting vector · Intensity of EM wave · Radiation pressure · Radio waves · Microwaves · Infrared