Question

What is the energy of the electron revolving in third orbit expressed in eV?

• A. 1.51 eV
• B. 3.4 eV
• C. 4.53 eV
• D. 4 eV

Answer 1

The correct option is A 1.51 eV

Energy of electron in nth state of hydrogen atom $E_n=\frac{-13.6}{n^2}$ $eV$

Thus energy of electron revolving in third $(n=3)$ orbit, $E_3=\frac{-13.6}{3^2}$ $eV$

$⟹$ $E_3=-1.51$ $eV$