The electromagnetic spectrum

In a nutshell

All light waves are a type of wave called an electromagnetic wave. Electromagnetic waves form a spectrum over a range of frequencies made up of: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays.

Electromagnetic waves

Electromagnetic waves are transverse waves. All electromagnetic waves travel at the same speed through air or a vacuum, the speed of light. They transfer energy as radiation from the waves' source to an absorber.

Example

Light waves are a type of electromagnetic wave.

The electromagnetic spectrum

Electromagnetic waves consist of more than just the light humans can see. Human eyes are only able to see the frequency range of visible light.

Curiosity: Visible light is only a very small range of frequencies in the electromagnetic spectrum!

There are seven different types of electromagnetic waves which each correspond to a certain range of frequencies and wavelengths.

Type	Frequency	Wavelength
Radio waves	Lowest	Highest	$1 \:m\: - 10^{4} \:m$
Microwaves	$\downarrow$	$\uparrow$	$10^{-2}\:m$
Infrared			$10^{-5}\:m$
Visible light			$10^{-7}\:m$
Ultraviolet			$10^{-8} \:m$
X-rays			$10^{-10} \:m$
Gamma rays	Highest	Lowest	$10^{-15} \:m$

Note: The wavelength isn't always given by a range but instead an order of magnitude. You do not need to remember these, just know that wavelength decreases down the table.

Tip: Try and come up with a mnemonic to remember the spectrum. The first letters are RMIVUXG. Some people like to use Raging Martians Invaded Venus Using X-Ray Guns, but bonus points if you can come up with your own!