An electron of a stationary hydrogen atom passes from the fifth energy level to

⇦

⇨

An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be: (m is the mass of electron, R, Rydberg constant and h Planck’s constant)

Options

(a) 24hR / 25m
(b) 25hR / 24m
(c) 25m / 24hR
(d) 24m / 25hR

Correct Answer:

24hR / 25m

Explanation:

For emission, the wave no. of the radiation is given as
1/λ = Rz² (1/n₁² – 1/n₂²)
R = Rydberg constant, Z = atomic number
= R (1/1² – 1/5²) = R (1 – 1/25) ⇒ 1/λ = R 24/25
linear momentum
P = h/λ = h x R x 24/25 (de-Broglie hypothesis)
⇒ mv = 24hR / 25 ⇒ V = 24hR / 25m

Related Questions:

1. Reactance of a capacitor of capacitance C µF for A.C freqency (400 / π) Hz is 25 ohm
2. Consider a uniform square plate of side ɑ and mass m. The moment of inertia
3. Two wires of equal length and equal diameter and having resistivities ρ₁ and ρ₂
4. A nucleus of mass number 220, initially at rest, emits an α-particle. If the Q-value
5. A small object of uniform density rolls up a curved surface with an initial velocity

Topics: Atoms and Nuclei (136)
Subject: Physics (2479)

---

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

---

Share this page with your friends