Chapter 38 - Photons and Matter Waves - Problems - Page 1181: 6

$E = 2.11~eV$

We can find the photon energy: $E = \frac{hc}{\lambda}$ $E = \frac{(6.63\times 10^{-34}~J\cdot s)(3.0\times 10^8~m/s)}{589\times 10^{-9}~m}$ $E = 3.377\times 10^{-19}~J$ $E = (3.377\times 10^{-19}~J)(\frac{1~eV}{1.6\times 10^{-19}~J})$ $E = 2.11~eV$