# How can you express the energy of photon?

The energy of a photon can be expressed as E = h.nu where h is Plank’s constant as we will as nu is the frequency of the mode of the harmonic oscillator to which the photon belongs. As h = 6 63×10-34 Js as we will as is a constant, energy can be added or subtracted in steps only; that is, energy is quantized.