Answer:
Gamma rays
Step-by-step explanation:
Assuming you are talking about electromagnetic waves, the answer is gamma rays.
In fact, electromagnetic waves are oscillations of the electric and the magnetic field in a plane perpendicular to the direction of motion the wave.
All electromagnetic waves travel in a vacuum at the same speed, the speed of light:
Electromagnetic waves are also classified into 7 different types, according to their wavelength/frequency. From highest to lowest frequency, we have:
Gamma rays
X rays
Ultraviolet
Visible light
Infrared radiation
Microwaves
Radio waves
Moreover, the energy of an electromagnetic wave is proportional to its frequency, according to
where h is the Planck constant and f is the frequency. It follows that the waves with more energy are the waves with highest frequency: therefore, gamma rays.