Physics - Electromagnetic spectrum

Electromagnetic spectrum

The electromagnetic spectrum is a continuous range of wavelengths. The types of radiationthat occur in different parts of the spectrum have different uses and dangers - depending on their wavelength and frequency.

The order of electromagnetic waves in the spectrum is shown in the table.

EnergyFrequencyWavelengthRadiation typeTypical use Lowest Lowest Longest Radio waves Television signals Microwaves Cooking, mobile phones Infrared Optical fibre communication Visible light Seeing Ultraviolet Detecting forged bank notes X-rays Medical images of bones Highest Highest Shortest Gamma radiation Killing cancer cells

Radio waves have the lowest frequencies and longest wavelengths, while gamma waves have the highest frequencies and shortest wavelengths.

All of these waves travel at the same speed in free space, which is the speed of light or about 300,000,000 m/s (metres per second).

White light can be split up to form a spectrum using a prism. This is a block of glass with a triangular cross section.

The light waves are refractedas they enter and leave the prism. The shorter the wavelength of the light, the more it…