(a) Let \(v_{0}\) be the threshold frequency. Then \(h v_{0}=w_{0}\)
or \(\quad v_{0}=\frac{\omega_{0}}{\mathrm{~h}}=\frac{2.14 \mathrm{eV}}{6.63 \times 10^{-34}}=5.16 \times 10^{4} \mathrm{~Hz}\)
(b) \(\mathrm{eV}_{\mathrm{s}}=\mathrm{h} v-\mathrm{o}_{0}=\frac{\mathrm{hc}}{\lambda}-\omega_{0}\)
or \(\lambda=\frac{\text { he }}{\mathrm{eV}_{\mathrm{s}}+\mathrm{ea}_{0}}\)
\(\lambda=\frac{6.63 \times 10^{-34} \times 3 \times 10^{8}}{(0.60 \mathrm{eV}+2.14 \mathrm{eV})}=\frac{19.89 \times 10^{-26}}{2.74 \times 1.6 \times 10^{-40}}\) \(=454 \mathrm{~nm}\)
