If by greatest frequency you mean highest frequency, we know that the upper end of the electromagnetic spectrum has the greatest frequency. This is the home to the gamma rays. They have the highest frequency, shortest wavelength, and the greatest energy.
Gamma rays have the shortest wavelength. Electromagnetic wave is a kind of energy being propagated even through free space (vacuum). It is classified based on the mode of producing it as Radio waves, micro waves, infra red, visible, ultra violet, X-ray and Gamma ray. Out of these seven, radio waves have the lowest frequency and Gamma ray has the highest frequency. As frequency and wavelength are inversely related, radio wave would have the longest wavelength.
As you go farther right down the spectrum (radio waves, microwaves, infrared waves, visible light, ultraviolet light, x-rays, and gamma rays), the waves' wavelengths decrease as their frequencies decrease. For example, x-rays have a shorter wavelength and higher frequency than ultraviolet light. Radio waves on the left end have the longest wavelength and shortest frequency, while gamma rays on the right end have the shortest wavelength and highest frequency.
They're not comparable. -- Cosmic rays are high-energy charged particles moving at less than the speed of light, with mass and kinetic energy but no characteristic frequency or wavelength. -- Gamma rays are electromagnetic radiation.
Generically speaking, radio waves have the longest wavelength and gamma rays have the highest energy.
Gamma Rays.
Gamma rays emit the highest frequency.
There is no such thing as the highest frequency. Since photons or electromagnetic travel at the speed of light its frequency correlates to the energy. The highest energy, and thus the highest frequency, is found in cosmic radiation, where a single photon may carry many millions of kiloelectronvolts.
the answer is gamma rays
The highest frequencies of waves are gamma rays.
Gamma Rays
gamma has the highest frequency because on a wave chart the gamma rays have the most energy and frequency
The highest frequency is gamma rays And the lowest is radio waves
Gamma rays
Gamma rays.
Gamma Rays are the highest frequency waves. Lower than that are X-rays then Ultraviolet. Then visible light, infrared, microwave, and radio waves are the lowest frequency. Here is a link which gives more information http://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html
I don't think there is a limit, as to how high the frequency can get. The EM waves of the highest energy (and frequency) are called "gamma rays".