Question

A hydrogen atom in its ground state absorbs 10.2 eV of energy. The angular momentum of electron of the hydrogen atom will increase by the value of: (Given, Planck’s constant = $6.6 × 10^{–34}$ Js).

• A. $2.10 × 10^{–34}$ Js
• B. $1.05 × 10^{–34}$ Js
• C. $3.15 × 10^{–34}$ Js
• D. $4.2 × 10^{–34}$ Js

Answer 1

Answer: (B)

$1.05 × 10^{–34}$ Js

Answer 2

$-13.6+10.2=\frac{-13.6}{n^2}$

$⇒ \frac{13.6}{n^2} = 3.4$

$⇒ n = 2$

$⇒ Δ L = 2 \times \frac{h}{2λ} - 1 \times \frac{h}{2λ}$

$⇒ \frac{h}{2λ}$

$⇒ Δ L ≅ 1.05 \times 10^{-34} \;J\;s$

Hence, the correct option is (B): $1.05 × 10^{–34}$ $J s$