Physics - Modern Physics Question with Solution | TestHub

We know that,

$E_n=\frac{13.6}{n^{\mathrm{2 }}}$$\mathrm{eV}$

According to question, the required energy is

$E=E_2-E_4$

$\frac{13.6}{{\left(2\right)}^2}-\frac{13.6}{4^2}=\frac{13.6}{4}-\frac{13.6}{16} \mathrm{eV}$

$=\frac{\left(13.6\times 4\right)-13.6}{16}$$\mathrm{eV}$

$=\frac{40.8}{16}=+2.55$$\mathrm{eV}$