Question

Energy of the electron in $n^{th}$ orbit of hydrogen atom is given by $E_n=-\frac{13.6}{n^2}eV$. The amount of energy needed to
transfer electron from first orbit to third orbit is

• A. 13.6 eV
• B. 3.4 eV
• C. 12.09 eV
• D. 1.51 eV

Answer 1

The correct option is C 12.09 eV

Using $E=-\frac{13.6}{n^2}eV$
For n = 1, $E_1=\frac{-13.6}{1^2}=-13.6eV$ and for n = 3 $E_3=-\frac{13.6}{3^2}=-1.51eV$
So required energy $=E_3-E_1=-1.51-(-13.6)=12.09eV$