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Question: Answered & Verified by Expert
A hydrogen atom in ground state absorbs \( 10.2 \mathrm{eV} \) of energy. The orbital angular momentum of
the electron is increased by
PhysicsAtomic PhysicsKCETKCET 2019
Options:
  • A \( 3.16 \times 10^{-34} \mathrm{Js} \)
  • B \( 1.05 \times 10^{-34} \mathrm{Js} \)
  • C \( 4.22 \times 10^{-34} \mathrm{Js} \)
  • D \( 2.11 \times 10^{-34} \mathrm{~J}_{S} \)
Solution:
2614 Upvotes Verified Answer
The correct answer is: \( 1.05 \times 10^{-34} \mathrm{Js} \)
(B)
By absorbing \( 10.2 \mathrm{ev} \), electron goes to \( 2 \) nd orbit as
\[
\begin{array}{l}
E_{1}=-13.6 \mathrm{eV} \\
E_{2}=-3.4 \mathrm{eV} \\
E_{2}-E_{1}=10.2 \mathrm{eV} \\
L_{2}-L_{1}=\frac{n_{2} h}{2 \pi}-\frac{n_{1} h}{2 \pi}=\frac{2 h}{2 \Pi}-\frac{h}{2 \pi}=\frac{6.62 \times 10^{-34}}{2 \times 3.14} \\
=1.05 \times 10^{-34} \mathrm{Js}
\end{array}
\]

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