Chemistry and Chemical Reactivity (9th Edition)

Energy required by the atom is the same as the one provided by the photon: $E=h\times\nu$ $6.7\times 10^{-19}\ J=6.626\times10^{-34}\ J.s\times \nu$ $\nu=10.11\times10^{14}\ 1/s$ $c=\lambda\times\nu$ $\lambda=2.998\times10^8\ m/s\div 10.11\times10^{14}\ 1/s$ $\lambda=2.96\times10^{-7}\ m=296\ nm$ No, the maximum wavelength allowed for the switch to work is 296 nm.