Electromagnetic spectrum

Definition

The electromagnetic spectrum encompasses all types of electromagnetic radiation, ranging from gamma rays to radio waves. It is organized by wavelength and frequency.

5 Must Know Facts For Your Next Test

1. The electromagnetic spectrum includes, in order of increasing wavelength, gamma rays, X-rays, ultraviolet light, visible light, infrared radiation, microwaves, and radio waves.
2. Visible light is the only part of the electromagnetic spectrum that can be seen by the human eye.
3. Different types of electromagnetic radiation are used for various astronomical observations; for example, radio waves for studying distant galaxies and X-rays for observing black holes.
4. The speed of light in a vacuum is constant across all types of electromagnetic radiation and is approximately 299,792 kilometers per second.
5. Wavelength and frequency are inversely related: as the wavelength increases, the frequency decreases.

Review Questions

• What are the different segments of the electromagnetic spectrum in order from shortest to longest wavelength?
• Why is visible light unique within the electromagnetic spectrum?
• How are wavelength and frequency related in the context of the electromagnetic spectrum?

Related terms

Wavelength:

The distance between successive crests of a wave; it determines the type of radiation within the electromagnetic spectrum.

Frequency:

The number of waves that pass a given point per second; higher frequencies correspond to shorter wavelengths.

Photon:

A particle representing a quantum of light or other electromagnetic radiation; photons carry energy proportional to their frequency.