Answer: Longest wavelength - Radio wave
Shortest wavelength - Gamma wave
Step-by-step explanation:
Radio waves have longer wavelengths and they have low energy in the electromagnetic spectrum. These waves have low frequency as well. Such waves are used for radio communication as they can help in transfer of signals due to longer wavelength, satellites and computer networks.
Gamma waves have shortest wavelength in the electromagnetic spectrum. They have have the highest frequencies. These are the penetrating rays and they are produced by the radioactive decay of nuclei of the atom. These waves are used for sterilization and also for disinfection.