If the binding energy of the electron in a hydrogen atom is 13.6 eV, the energy required to remove the electron from the first excited state of $Li^{2+}$ is
Answer & explanation
Correct answer: option 1
$\text{Energy required to make a transition from energy state n to m is }$
$\Delta E = -13.6 z^2(\frac{1}{n^2} - \frac{1}{m^2}) = -13.6 \times 3^2(\frac{1}{2^2} - \frac{1}{\infty^2}) = 30.6 eV$