## Chemistry and Chemical Reactivity (9th Edition)

$c=\lambda\times\nu$ $\nu=2.998\times10^8\ m/s\div 410 \times10^{-9}\ m=7.31\times10^{14}\ 1/s$ Per photon: $E=h\times\nu$ $E=6.626\times10^{-34}\ J.s\times 7.31\times10^{14}\ 1/s=4.85\times10^{-19}\ J$ Per mole: $E=4.85\times10^{-19}\ J\times6.022\times10^{23}\ 1/mol=291.77\ kJ/mol$ Since red light has a higher wavelength, it has a smaller frequency and energy.