Question

The energy of an electron in $n^{th}$ orbit of the hydrogen atom is given by $E_n = -\frac{13.6}{n^2} eV$. The energy required to raise an electron from the first orbit to the second orbit will be

• A. $10.2 \,eV$
• B. $12.1 \,eV$
• C. $13.6 \,eV$
• D. $3.4 \,eV$

Answer 1

Answer: (A)

$10.2 \,eV$

Answer 2

$E_{1} = - \frac{13.6}{1^{2}} = -13.6 \,eV$ $E_{2} = - \frac{13.6}{2^{2}} = -3.4 \,eV$ $E = E_{2} - E_{1} = -3.4\,eV-\left(-13.6\right)\,eV$ $=10.2 \,eV$