A hydrogen atom makes a transition from n = 2 to n = 1 and emits a photon.  This photon strikes a doubly ionized lithium atom  (z = 3) in excited state and completely removes the orbiting electron.  The least quantum number for the excited state of the ion for the process is :

  • Option 1)

     2

  • Option 2)

    3

  • Option 3)

     4

  • Option 4)

    5

 

Answers (1)

As we learnt in

Energy emitted due to transition of electron -

\Delta E= Rhcz^{2}\left ( \frac{1}{n_{f}\, ^{2}}-\frac{1}{n_{i}\, ^{2}} \right )

\frac{1}{\lambda }= Rz^{2}\left ( \frac{-1}{n_{i}\, ^{2}}+\frac{1}{n_{f}\, ^{2}} \right )

- wherein

R= R hydberg\: constant

n_{i}= initial state \\n_{f}= final \: state

 

 Energy emitted by Hydrogen atom =1.36 \left(1-\frac{1}{4} \right )=10.2\ eV

So 10.2 eV photon removes an electron from nth orbital of Lithium.

Hence, Energy of nth orbital of Lithium should be - 10.2 eV.

\because\ \;E_{n}.\frac{z^{2}}{n^{2}}=-13.6\times\frac{9}{n^{2}}=-10.2

n^{2}\geq\frac{-13.6\times 9}{-10.2}=12

n\geq\sqrt{12}

Hence, Value of n = 4

Correct option is 3


Option 1)

 2

This is an incorrect option.

Option 2)

3

This is an incorrect option.

Option 3)

 4

This is the correct option.

Option 4)

5

This is an incorrect option.

Preparation Products

Knockout JEE Main April 2021 (One Month)

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Mentorship from our Experts, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 14000/- ₹ 4999/-
Buy Now
Knockout JEE Main May 2021

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Mentorship from our Experts, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 22999/- ₹ 9999/-
Buy Now
Test Series JEE Main May 2021

Unlimited Chapter Wise Tests, Unlimited Subject Wise Tests, Unlimited Full Mock Tests, Get Personalized Performance Analysis Report,.

₹ 6999/- ₹ 2999/-
Buy Now
Knockout JEE Main May 2022

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Mentorship from our Experts, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 34999/- ₹ 14999/-
Buy Now
JEE Main Rank Booster 2021

Booster and Kadha Video Lectures, Unlimited Full Mock Test, Adaptive Time Table, 24x7 Doubt Chat Support,.

₹ 13999/- ₹ 6999/-
Buy Now
Boost your Preparation for JEE Main 2021 with Personlized Coaching
 
Exams
Articles
Questions