Photon energy is proportional to which of the following. a. speed of light in a vacuum. B frequency of the light emitting the photon. C intensity of the light emmitting the photon. D wavelegnth of light emmitting thr photon.

We have that according to the quantum theory from Planck, E=h*f where h is a constant and f is the frequency, thus B is correct. Let's analyze the other choices: The speed of light in vacuum is irrelevant to the energy of the photon. The instensity of a light source is correlated to the amount of photons in that light beam but it does not affect individual photons. Finally, if l is the wavelength of light, l*f=c. Substituting this in the first equation we see that photon energy is inversely proportional to the wavelength.