Physics - Modern Physics Question with Solution | TestHub

The kinetic energy of an electron

$K =\frac{{Ze}^2}{8\pi {\epsilon }_{0}r}$

The potential energy of an electron

$U =-\frac{1}{4\pi {\epsilon }_0}\frac{{Ze}^2}{r}$

$\therefore$Total energy

$E = K +U =$$\frac{{Ze}^2}{8\pi {\epsilon }_{0}r}- \frac{{Ze}^2}{4\pi {\epsilon }_{0}r}$

Or$E=-\frac{{Ze}^2}{8\pi {\epsilon }_{0}r}$

Or$E=-K$

Or$K=-E= -(-3.4)$

Or$\mathrm{ }=3.4\mathrm{ }\mathrm{e}\mathrm{V}$