JEE Main 2016PhysicsAtomic PhysicsMediumMCQ

JEE Main 2016 — Atomic Physics Question with Solution

JEE Main 2016 (09 Apr Online)

Question

An electron in a hydrogen atom makes a transition from n=2 to n=1 and emits a photon. This photon strikes a doubly ionized lithium atom which was already in an excited state and completely removes the orbiting electron. The least quantum number for the excited state of the lithium-ion for the process is

Choose an option

Show full solutionCorrect option: B
Correct answer
B4

Step-by-step explanation

Let us assume that the electron in the lithium-ion is knocked off from the nth energy level, then

RZH2112−122=RZLi2n2

R12×34=R321n2

34=9n2

n=12≈3.5

Hence the least quantum number must be 4.

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About this question

This is a previous-year question from JEE Main 2016, covering the Atomic Physics chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.