Get 2 FREE Instant-Explanations on Filo with code FILOAPP

Home

Physics Part-II

Atoms

The total energy of an electron in the first excited state of

Physics Part-II

Class 12

NCERT

Chapter 1: Ray Optics and Optical Instruments

41 questions

Chapter 2: Wave Optics

30 questions

Chapter 3: Dual Nature of Radiation and Matter

44 questions

Chapter 4: Atoms

23 questions

12.14.

Classically, an electron can be in any orbit around the nucleus of an atom. Then what deteres the typical atomic size? Why is an atom not, say, thousand times bigger than its typical size? The question had greatly puzzled Bohr before he arrived at his famous model of the atom that you have learnt in the text. To simulate what he might well have done before his discovery, let us play as follows with the basic constants of nature and see if we can get a quantity with the dimensions of length that is roughly equal to the known size of an atom

(1 0^{- 10} m)

(a) Construct a quantity with the dimensions of length from the fundamental constants

e, m_{e}, an d c

. Detere its numerical value.

The total energy of an electron in the first excited state of the hydrogen atom is about

- 3.4 e V

(a)

What is the kinetic energy of the electron in this state?

(b)

What is the potential energy of the electron in this state

(c)

Which of the answers above would change if the choice of the zero of potential energy is changed?

If Bohrs quantisation postulate (angular momentum =

nh / 2 π

) is a basic law of nature, it should be equally valid for the case of planetary motion also. Why then do we never speak of quantisation of orbits of planets around the sun?

View all question

Chapter 5: Nuclei

38 questions

Chapter 6: Semiconductor Electronics: Materials, Devices and Simple Circuits

25 questions

Question

Medium

Solving time: 5 mins

The total energy of an electron in the first excited state of the hydrogen atom is about $- 3.4 e V$ .
$(a)$ What is the kinetic energy of the electron in this state?
$(b)$ What is the potential energy of the electron in this state
$(c)$ Which of the answers above would change if the choice of the zero of potential energy is changed?

Name: Video solution 1: [Solved] The total energy of an electron in the first excited state of the hydrogen atom is about −3.4eV.(a) What is the kinetic energy of the electron in this state?(b) What is the potential energy of the electron in this state(c) Which of the answers above would change if the choice of the zero of potential energy is changed? - Physics Part-II
Uploaded: 2022-12-06T02:19:17.000Z
Duration: 7 min
Description: Video solution 1: [Solved] The total energy of an electron in the first excited state of the hydrogen atom is about −3.4eV.(a) What is the kinetic energy of the electron in this state?(b) What is the potential energy of the electron in this state(c) Which of the answers above would change if the choice of the zero of potential energy is changed? - Physics Part-II

Views: 5,622 students

Updated on: Dec 6, 2022

Book:

Physics Part-II (NCERT)

Found 6 tutors discussing this question

Lucas Discussed

The total energy of an electron in the first excited state of the hydrogen atom is about

- 3.4 e V

(a)

What is the kinetic energy of the electron in this state?

(b)

What is the potential energy of the electron in this state

(c)

Which of the answers above would change if the choice of the zero of potential energy is changed?

10 mins ago

Discuss this question LIVE

10 mins ago

Text solutionVerified

In Bohrs model, mvr = nh and

\frac{m v ^{2}}{r} = \frac{Z e ^{2}}{4 π ε _{0} r ^{2}}

, which give,

T = \frac{1}{2} m v^{2} = \frac{Z e ^{2}}{8 π ε _{0} r}; r = \frac{4 π ε _{0} h ^{2}}{Z e ^{2} m} n^{2}

These relations have nothing to do with the choice of the zero of potential energy. Now, choosing the zero of potential energy at infinity, we have

V = - (Z e^{2} /4 π ε_{0} r)

, which gives

V = - 2 T

and

E = T + v = - T

(a) The quoted value of E = 3.4 eV is based on the customary choice of zero of potential energy at infinity. Using E = T, the kinetic energy of the electron in this state is + 3.4 eV.

(b) Using V = 2T, potential energy of the electron is = 6.8 eV.

(c) If the zero of potential energy is chosen differently, kinetic energy does not change. Its value is + 3.4 eV independent of the choice of the zero of potential energy. The potential energy, and the total energy of the state, however, would alter if a different zero of the potential energy is chosen.

Was this solution helpful?

Report

Filo tutor solutions (1)

Learn from their 1-to-1 discussion with Filo tutors.

7 mins

Uploaded on: 12/6/2022

Ask your question, on a video call with tutor

Connect instantly with this tutor

Connect now

Taught by

Akhil

Total classes on Filo by this tutor - 3,554

Teaches : Physics, Biology, Organic Chemistry

Connect instantly with this tutor

Connect now

Notes from this class (3 pages)

Download

Was this solution helpful?

Report

One destination for complete JEE/NEET preparation

One destination to cover all your homework and assignment needs

Learn Practice Revision Succeed

Instant 1:1 help, 24x7

60, 000+ Expert tutors

Textbook solutions

Big idea maths, McGraw-Hill Education etc

Essay review

Get expert feedback on your essay

Schedule classes

High dosage tutoring from Dedicated 3 experts

Trusted by 4 million+ students

Practice more questions from Physics Part-II (NCERT)

12.14.

(1 0^{- 10} m)

(a) Construct a quantity with the dimensions of length from the fundamental constants

e, m_{e}, an d c

. Detere its numerical value.

The total energy of an electron in the first excited state of the hydrogen atom is about

- 3.4 e V

(a)

What is the kinetic energy of the electron in this state?

(b)

What is the potential energy of the electron in this state

(c)

Which of the answers above would change if the choice of the zero of potential energy is changed?

If Bohrs quantisation postulate (angular momentum =

nh / 2 π

) is a basic law of nature, it should be equally valid for the case of planetary motion also. Why then do we never speak of quantisation of orbits of planets around the sun?

View all

Stuck on the question or explanation?

Connect with our Physics tutors online and get step by step solution of this question.

231 students are taking LIVE classes

Question Text	The total energy of an electron in the first excited state of the hydrogen atom is about $- 3.4 e V$ . $(a)$ What is the kinetic energy of the electron in this state? $(b)$ What is the potential energy of the electron in this state $(c)$ Which of the answers above would change if the choice of the zero of potential energy is changed?
Updated On	Dec 6, 2022
Topic	Atoms
Subject	Physics
Class	Class 12
Answer Type	Text solution:1 Video solution: 1
Upvotes	137
Avg. Video Duration	7 min

Text solutionVerified

Filo tutor solutions (1)

Practice more questions from Physics Part-II (NCERT)

Practice questions from Physics Part-II (NCERT)

Practice more questions from Atoms

Practice questions on similar concepts asked by Filo students

Text solutionVerified

Filo tutor solutions (1)

Practice more questions from Physics Part-II (NCERT)

Practice questions from Physics Part-II (NCERT)

Practice more questions from Atoms

Practice questions on similar concepts asked by Filo students

Related books for questions on Atoms