Describe how the electromagnetic spectrum is arranged in terms of frequency and wavelength, and state one use for each of the following types of electromagnetic radiation: infrared and radio waves.

The electromagnetic spectrum is arranged in order of decreasing frequency (and increasing wavelength). It starts with gamma rays at the highest frequency and shortest wavelength, followed by X‑rays, ultraviolet, visible light, infrared, microwaves and finally radio waves at the lowest frequency and longest wavelength.

Infrared radiation is used in heating appliances such as infrared heaters and in night‑vision devices.

Radio waves are used for broadcasting radio and television signals, and for wireless communication such as mobile phones.