Question

According to Bohr's theory of hydrogen atom, the approximate angular momentum of electron in H atom in the ground state is ($h = 6.62 \times 10^{-34}$ Js):

• A. $1.05 \times 10^{-34}$ J
• B. $1.05 \times 10^{-34}$ Js
• C. $6.62 \times 10^{+34}$ J
• D. $6.62 \times 10^{-34}$ Jm

Hint:

Bohr model: $L = n \hbar$.
Ground state $n=1$.
Always divide $h$ by $2\pi$ for $\hbar$.
Check units carefully (Js).

Answer 1

The Correct Option is B

• Bohr's quantization: $L = n \hbar$, $n = 1$ for ground state.
• Reduced Planck's constant: $\hbar = h / 2\pi = 6.62 \times 10^{-34} / (2\pi) \approx 1.05 \times 10^{-34}$ Js.
• Hence, angular momentum in ground state = $1.05 \times 10^{-34$ Js}.