Formula: Photon Photon energy Frequency
$$W_{\text p} ~=~ h \, \class{violet}{f}$$
$$W_{\text p} ~=~ h \, \class{violet}{f}$$
$$\class{violet}{f} ~=~ \frac{ W_{\text p} }{ h }$$
$$h ~=~ \frac{ W_{\text p} }{ \class{violet}{f} }$$
Photon energy
$$ W_{\text p} $$ Unit $$ \mathrm{J} $$
Photon energy is the energy of a single photon (light particle). You can calculate it with the help of the light frequency \( f \). For example, if the light has the frequency \( f = 10^{15} \, \mathrm{Hz} \), then the energy of a photon is:
\begin{align}
W_{\text p} &= 6.6 \cdot 10^{-34} \, \mathrm{Js} ~\cdot~ 10^{15} \, \mathrm{Hz} \\\\
&= 6.6 \cdot 10^{-19} \, \mathrm{J}
\end{align}
Frequency
$$ f $$ Unit $$ \mathrm{Hz} $$
Frequency of electromagnetic radiation. For example, the frequency of green light is in the range \( f = 5.5 \cdot 10^{14} \, \mathrm{Hz}\).
The frequency can be written with the wavelength \(\lambda\) and the speed of light \(c\) as follows: $$ f = \frac{c}{\lambda} $$
Planck's Constant
$$ h $$ Unit $$ \mathrm{Js} $$
Planck's constant is a physical constant from quantum mechanics and has the value:
$$ h ~=~ 6.626 \, 070 \, 15 \,\cdot\, 10^{-34} \, \mathrm{Js} $$