Question

The angular momentum of an electron in the hydrogen atom is $\frac{3h}{2\pi }$. Here h is Planck's constant. The kinetic energy of this electron is:

• A. 4.53 eV
• B. 1.51 eV
• C. 3.4 eV
• D. 6.8 eV

Answer 1

Answer: (B)

1.51 eV

Angular momentum,

$L=\frac{nh}{2\pi }=\frac{3h}{2\pi }$ (given)

also $n=3$

$\therefore$ $E=\frac{-1.36}{n^2}eV$

$E=\frac{-13.6}{{\left(3\right)}^2}eV$

$E=\frac{-13.6}{9}eV$

$E=-1.57eV$