To solve this question, we need to use the equation relating energy of a wave to its wavelength.

Here, is the energy, is Planck’s constant, is speed of light (for us it’s always ), and is the wavelength (in meters). The energy of the ultraviolet rays is

If we look at the electromagnetic spectrum we will notice that the wavelength of radio waves is a lot higher than ultraviolet rays. Since energy is inversely proportional to wavelength we can conclude that the energy of radio waves is lower than ultraviolet's. The only answer choice with an energy lower than ultraviolet rays energy is 1.24neV.

Electromagnetic spectrum is a spectrum of different types of light. Each type of electromagnetic wave differs from one another based on the frequency and wavelength; however, the speed of every electromagnetic wave in air is . The wave equation relates the speed of an electromagnetic to its wavelength and frequency as follows.

Here, is speed of light, is wavelength, and is frequency. Since is always constant, wavelength and frequency are inversely proportional to each other. This means that if the wavelength increases the frequency decreases.

Photons are fundamental particles that make up electromagnetic waves (light). The key aspect of photon is that it has very high speed and no mass; therefore, mass for photons is always zero.