Physics - Modern Physics Question with Solution | TestHub

The change in energy is related to wavelength of photon emitted as:

$$\begin{gathered} ∆E=\frac{hc}{\lambda } \\ =\frac{6.62\times {10}^{-34} \mathrm{J} \mathrm{s}\times 3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}}{1.6\times {10}^{-19} \mathrm{J}\times 124.1 \mathrm{nm}} \\ =\frac{1242 \mathrm{eV} \mathrm{nm}}{124.1 \mathrm{nm}} \\ =10 \mathrm{eV} \end{gathered}$$

Hence, option D is correct.