Question

Energy required for the electron excitation in $L{i}^{++}$ from the first to the third Bohr orbit is :

• A. 36.3 eV
• B. 108.8 eV
• C. 122.4 eV
• D. 12.1 eV

Answer 1

The correct option is B 108.8 eV

$E=-13.6\frac{z^2}{n^2}$
$E_1=-13.6\times \frac{3^2}{1}=-13.6\times 9$
$E_3=-13.6\times \frac{3^2}{3^2}=-13.6$
$E_3-E_1=-13.6+(13.6\times 9)$
$=108.8eV$