Answer:
Radio waves have the longest wavelenghts.
Explanation:
Radio waves are the most low-frequency form of electromagnetic radiation. Radio waves have frequencies from 300 GHz down to 3 kHz, and corresponding wavelengths between 1 millimeter and 100 kilometers.
Radio waves can be created naturally by natural phenomena such as lightning, or astronomical objects. They can also be generated artificially and are used for fixed and mobile radio communications, broadcasting, radar and other navigation systems, communications satellites, telematic networks and many other applications.
