Chemistry - Atomic Structure Question with Solution | TestHub

$\lambda =3000\tilde{A}\dots =3\times 10^{-7}\mathrm{m},\varphi =2.13\mathrm{eV}$ K.E. $=hv-h{v}_0=hv-\varphi =\frac{hc}{\lambda }-\varphi$ $=\frac{\left(6.626\times 10^{-34}\times 3\times 10^8\right)}{3\times 10^{-7}}-\left(2.13\times 1.6\times 10^{-19}\right)$ $=\frac{1.98\times 10^{-25}}{3\times 10^{-7}}-\left(3.408\times 10^{-19}\right)$ $=\left(6.60\times 10^{-19}\right)-\left(3.408\times 10^{-19}\right)$ $=3.192\times 10^{-19}\mathrm{J}=2.0\mathrm{eV}$