Question

The energy required to knock out the electron in the third orbit of a hydrogen atom is equal to

• A. $13.6eV$
• B. $+\frac{13.6}{9}eV$
• C. $-\frac{13.6}{3}eV$
• D. $-\frac{3}{13.6}eV$

Answer 1

The correct option is B $+\frac{13.6}{9}eV$

Energy required to knock out the electron in the$n^{th}$ orbit $=+\frac{13.6}{n^2}eV\Rightarrow E_3=+\frac{13.6}{9}eV$