Physics - Modern Physics Question with Solution | TestHub

Energy of an electron in n^thorbit of an ion with atomic number$z$is,$E=-13.6\times \frac{z^2}{n^2} \mathrm{eV}$

for$1^{\mathrm{st}}$excited state of$L{i}^{++}, z=3, n=2$

$E=-13.6\times \frac{3^2}{n^2}=-13.6\times \frac{9}{4} \mathrm{eV}$

$= -30.6 \mathrm{eV}$

$\therefore$Required energy$=30.6 \mathrm{eV}$