Question

What is the formula for calculating the energy of a photon?

E = h – f
E = h over f
E = h + f
E = hf

Answer 1

E = hf

Here h is Planck’s constant (h ≈ 6.626×10^−34 J·s) and f is the photon frequency.
You can also write E = hc/λ, where c is the speed of light and λ the wavelength.