Which of the following has the lowest wavelength?
Gamma rays
The electromagnetic spectrum is the distribution of electromagnetic radiation according to the energy (or equivalently according to frequency or wavelength). It is generally divided into seven regions, in the order of increasing wavelength and decreasing energy and frequency: Gamma rays, X rays, Ultraviolet rays, Visible light, Infrared rays, Microwaves, and Radio waves.
Among the main types of electromagnetic radiation, Radio waves have the lowest frequencies(least energetic) and longest wavelengths, while gamma waves have the highest frequencies(more energetic) and shortest wavelengths.
So, Gamma rays have the lowest wavelength.