In 1905, approximately 100 years ago, Albert Einstein revolutionized physics and our understanding of the universe. One of his revolutionary ideas was that light is composed of particles called photons that have zero mass but do have energy.
The energy of a photon is proportional to its frequency.
Because of this proportionality, high frequency light has high energy, and low frequency light has low energy.
Wavelength is inversely proportional to frequency. Therefore, long (or high) wavelength light has low energy, and short (or low) wavelength light has high energy.
Which extreme end of the electromagnetic spectrum has the highest energy, gamma rays or radio waves?