Using the functions given in Table 7.4, verify that for the more circular electron orbit in hydrogen (i.e.,l=n-1), the radial probability is of the form

P(r)r2ne-2r/nao

Show that the most probable radius is given by

rmostprobable=n2ao

Short Answer

Expert verified

The most probable radius isr=n2a0.

Step by step solution

01

 Given data

The radial function for l=n-1is,

role="math" localid="1659182273339" Rn,n-1rn-1e-r/(nao)

02

 Concept

The most probable radius is the radius of the orbit in which the probability of finding the electron is maximum.

The probability density is

P(r)=r2R2n,n-1

03

 Solution

P(r)=r2R2n,n-1=r2rn-1e-r/(nao)=r2r2n-2e-r/(nao)=r2ne-r/(nao)

To find the most probable location, take the derivative of the probability density,

dPrdr=ddrr2ne-2rlna°=2nr2n-1e-2rlna°+r2n-2na°e-2rlna°=e-2rlna°r2n-12n+-2rna°

For the most probable location, the derivative should be equal to zero.

role="math" localid="1659182748704" =e-2rlna°r2n-12n+-2rna°

Hence,

2n+-2rna°=0r=n2a°

The most probable radius is r=n2a°.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

At heart, momentum conservation is related to the universe being "translationally invariant," meaning that it is the same if you shift your coordinates to the right or left. Angular momentum relates to rotational invariance. Use these ideas to explain at least some of the differences between the physical properties quantized in the cubic three-dimensional box versus the hydrogen atom.

Consider a cubic 3D infinite well.

(a) How many different wave functions have the same energy as the one for which (nx,ny,nz)=(5,1,1)?

(b) Into how many different energy levels would this level split if the length of one side were increased by 5% ?

(c) Make a scale diagram, similar to Figure 3, illustrating the energy splitting of the previously degenerate wave functions.

(d) Is there any degeneracy left? If so, how might it be “destroyed”?

In hydrogen’s characteristic spectra, each series - the Lyman, the Balmer, and so on – has a “series limit,” where the wavelengths at one end of the series tend to bunch up, approaching a single limiting value. Is it at the short-wavelength or the long-wavelength end of the series that the series limit occurs, and what is it about hydrogen’s allowed energies that leads to this phenomenon? Does the infinite well have series limits?

Spectral lines are fuzzy due to two effects: Doppler broadening and the uncertainty principle. The relative variation in wavelength due to the first effect (see Exercise 2.57) is given by

λλ=3kBT/mc

Where T is the temperature of the sample and m is the mass of the particles emitting the light. The variation due to the second effect (see Exercise 4.72) is given by

λλ=λ4πc

Where, t is the typical transition time

(a) Suppose the hydrogen in a star has a temperature of 5×104K. Compare the broadening of these two effects for the first line in the Balmer series (i.e.,ni=3nf=2 ). Assume a transition time of 10-8s. Which effect is more important?

(b) Under what condition(s) might the other effect predominate?

Taking then=3states as representative, explain the relationship between the complexity numbers of nodes and antinodes-of hydrogen's standing waves in the radial direction and their complexity in the angular direction at a given value of n. Is it a direct or inverse relationship, and why?

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free