Final answer:
The energy of a photon is represented by the equation E = hf, with 'h' as Planck's constant and 'f' as the photon's frequency. The correct answer to the question is D. Energy and momentum are direct properties of a photon which is massless.
Step-by-step explanation:
The energy of a photon is given by the equation E = hf, where E is the energy, h is Planck's constant, and f is the frequency of the photon. This relationship shows that energy is directly proportional to frequency, meaning that as the frequency of a photon increases, so does its energy. It's also important to note that a photon is a quantum packet of energy that is massless, as different from other fundamental particles that have mass.
The correct answer from the provided options is D. The energy of a photon is h * f. This equation can also be written in terms of wavelength λ (lambda), using the speed of light c, as E = hc/λ. Photons, despite having no rest mass, have momentum that is related to their energy.