Final answer:
3. A photon of ultraviolet light has the greatest energy as compared to photons of infrared and visible light since energy in the electromagnetic spectrum increases with frequency, and ultraviolet has a higher frequency than the other two.
Step-by-step explanation:
The question is asking which photon has the greatest energy among a photon of infrared light, visible light, and ultraviolet light. According to the electromagnetic spectrum, the energy of a photon is directly proportional to its frequency. The order of increasing energy in the electromagnetic spectrum from low to high energy is as follows: Radio, Microwave, Infrared, Visible, Ultraviolet, X-ray, and Gamma rays. Visible light photons have energies ranging from about 1.63 eV (red) to 3.26 eV (violet). Ultraviolet photons have higher energies than visible light photons as they are of higher frequency. Therefore, out of the three options given, a photon of ultraviolet light carries the greatest amount of energy.