Formula anchor$$ \begin{align} W_{\text p} ~=~ h \, \frac{c}{\lambda} \end{align} $$

Here \( c ~=~ 3 \cdot 10^8 \, \frac{\mathrm m}{\mathrm s} \) is the speed of light and \( h ~=~ 6.6 \,\cdot\, 10^{-34} \, \mathrm{Js} \) is the Planck's constant. The energy \(W_{\text p}\) of a photon depends only on the wavelength \( \lambda \) of the light.

The energy of one mole of photons, let us call it \(W_{\text{mol}}\), is the energy \(W_{\text p}\) of a single photon multiplied by the number of photons per mole. The Avogadro constant \(N_{\text A} = 6 \cdot 10^{23} \, \frac{1}{\mathrm{mol}} \) provides us with the number of photons per mole. Therefore, the photon energy per mole is given by:

Photon energy per mole is the product of the Avogardo constant with the energy of a photon

+ Perfect for high school and undergraduate physics students + Contains over 500 illustrated formulas on just 140 pages + Contains tables with examples and measured constants + Easy for everyone because without vectors and integrals