Use the formula: (E = hf)
(E) = energy of the photon
(h) = Planck’s constant ((6.626 times 10^{-34} text{J·s}))
(f) = frequency of the photon
If wavelength is given, use: (E = dfrac{hc}{lambda})
(c) = speed of light ((3.00 times 10^8 text{m/s}))
(lambda) = wavelength
Convert wavelength to meters before calculating
Substitute the values into the formula
Calculate the result in joules
If needed, convert joules to electronvolts using (1 text{eV} = 1.602 times 10^{-19} text{J})