Question

$2^{n}d$ separation energy of an electron in H atom ?

• A. 27.2 ev
• B. 1.51 ev
• C. 3.4 ev
• D. 13.6 ev

Answer 1

Answer: (B)

1.51 ev

Energy separation is given by

$E_{n_2}-E_{n_1}=-13.6\times z^2[\frac{1}{n_2^2}-\frac{1}{n_1^2}]eV$

For $H,Z=1,2^{nd}$ excited state $n=3$,

$=13.6[\frac{1}{{\infty }^2}-\frac{1}{9}]$

$=-13.6(-\frac{1}{9})$

$=1.51eV$