By what percentage is the energy of a 500 nm photon greater than the energy of a 600 nm photon?

We give all the values ​​from given in the SI system:
λ1 = 500 nm. = 500 * 10 ^ -9 m.
λ2 = 600 nm. = 600 * 10 ^ -9 m.
Let’s write down the Einstein equation for the photoelectric effect:
h * ν = A + Tmax, where A is the work function of the electron from the metal, Tmax is the maximum kinetic energy of photoelectrons, h * ν is the photon energy.
E = h * ν
The radiation frequency is found from the expression:
ν = c / λ, where c is the speed of light c = 3 * 10 ^ 8 m / s, λ is the wavelength.
Let’s substitute in the photon energy:
E1 = h * s / λ1
E2 = h * s / λ2
substitute the numbers and find the energies:
E1 = h * s / λ1 = 6.63 * 10 ^ -34 * 3 * 10 ^ 8/500 * 10 ^ -9 = 3.978 * 10 ^ -19 J.
E2 = h * s / λ2 = 6.63 * 10 ^ -34 * 3 * 10 ^ 8/600 * 10 ^ -9 = 3.315 * 10 ^ -19 J.
(E1-E2) * 100% / E1 = (3.978 * 10 ^ -19-3.315 * 10 ^ -19) * 100% / (3.978 * 10 ^ -19) = 16.6%
Answer: the energy at a wavelength of 500 nm is 16.6% more.