Jaka jest energia w eV fotonu o długości fali 750 nm ?

[latex]dane:\lambda = 750 nm = 750cdot10^{-9} m = 7,5cdot10^{-7} m\h = 6,63cdot10^{-34} Jcdot s = 4,14cdot10^{-15} eVcdot s\c = 3cdot10^{8}frac{m}{s}\szukane:\E_{f} = ?[/latex] [latex]E_{f} = hcdot u\\ u = frac{c}{lambda}\\E_{f} = hcdotfrac{c}{lambda}\\E_{f} = 4,14cdot10^{-15}eVcdot s cdotfrac{3cdot10^{8}frac{m}{s}}{7,5cdot10^{-7}m}=1,656 eVapprox1,66 eV[/latex]