Question

If the binding energy of the electron in a hydrogen atom is $13.6eV$, the energy required to remove the electron from the first excited state of $L{i}^{++}$ is :

• A. $122.4eV$
• B. $30.6eV$
• C. $13.6eV$
• D. $3.4eV$

Answer 1

The correct option is B $30.6eV$

We know that:
$E=13.6\frac{z^2}{n^2}$

For $L{i}^{++},z=3$

Therefore,
$E=13.6\times \frac{3^2}{2^2}asn=2$

$E=30.6eV$