| an electromagnetic wave having a wavelength between 1 millimeter and 30,000 meters, or a frequency between 10 kilohertz and 300,000 megahertz. |
Waves at the end of the electromagnetic spectrum with the lowest frequency (less than 300 megahertz) and the longest wavelength (from a few feet to many miles). Because of their low frequency, radio waves carry very little energy compared to other electromagnetic waves. (See Planck's constant.)
Note: Radio waves can pass through the atmosphere and therefore are very useful for communication. Commercial, short-wave, and citizens' band radio are broadcast with radio waves, as is television.