Question

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

• A. $7.625\times {10}^{28}mev$
• B. $109ev$
• C. $8.8\times {10}^{-28}mev$
• D. $56ev$

Answer 1

Answer: (B)

$109ev$

$\begin{array}{c}\text{we know that energy for exitation of}{e}^{-}\text{is given as -}\\ E=13.6\times z^2\times [\frac{1}{n_1^2}-\frac{1}{n_2^2}]\\ \text{For exitation from first orbit}(n_1=1)\text{to third orbit}(n_2=3)\\ \text{we get}-E=13.6\times (3{)}^2\times [\frac{1}{1}-\frac{1}{9}]=108.8eV\\ E\approx 109eV\\ \text{Hence, option (B) is correct.}\end{array}$