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

Answer: (C)

12.09 Ev

Answer 2

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

$= E_{3} - E_{1} = - 1.51 - ( - 13.6) = 12.09eV$