Study Guide to Atomic Theory & Quantum Mechanics


DISCLAIMER: This Guide is not meant to be exhaustive. That is, I have tried to summarize the essential points of the lectures on this topic. The presence of a topic here does not guarantee a related question on an exam, nor are exam topics limited to what appears in this Guide. As with any Chemistry class, you are responsible for ALL of the assigned readings, problems and lecture material. Lectures will often contain information not covered or given less emphasis in the text.


Text Reading

Chapter 12 (pages 510-573)

 

What should you learn from this section of the course?

We have worked our way through the "history" of the development of quantum mechanics. You should know what each famous chemist/physicist did. You need not know any more detail than I presented, but you may find more in the text or the reserve reading. The Bohr model is not correct, but provides a chance to see just how quantum theory works. You should be comfortable with all of its details and the experimental application to the hydrogen atom (the Rydberg experiment you performed in the lab). Finally, we have developed the particle in a box model problem. You must be able to follow what we did and understand the implications. For hydrogen, we did not complete any derivation. We took the results from the Schroedinger equation and used them to examine hydrogen and hydrogen-like ions in detail. Finally, we examined the implications of many electrons in an atom by looking at periodic properties such as ionization energy and electron affinity. It is important for you to observe and rationalize periodic trends in any property.

 

General

The Bohr Atom

The Schroedinger Equation

Many Electron Atoms

 

Recommended Chapter 15 Problems

Light:  23, 25, 27, 29.  Bohr Model: 31, 33, 35.  Wave Mechanics  37, 41, 43, 45, 47.  Orbitals:  49, 51, 54, 55, 57.  Many Electron Atoms: 61, 65, 67, 73, 77.  The Periodic Table: 79, 81, 83, 85, 87, 91, 93, 95, 97, 107.  Mixed Concepts:  109, 111, 113, 121, 125, 131

 

Additional Problems

1.  The emission spectrum of the hydrogen atom has a line in the infrared at 18,900 Angstrom. Calculate the energy in Joules of a photon with this wavelength. Assign this transition by identifying the principal quantum numbers of the initial and final energy levels that are involved.

2.  Calculate the wavelength at which the series of lines to which the 18,900 Angstrom line belongs will have its series limit. What is the physical significance of this series limit? NOTE: A series of spectral lines in emission is characterized by a common value of nfinal -- i.e. the quantum number of the level at which the transition terminates.  The series limit for a series of emission lines is the wavelength that would correspond to the transition ninitial =    to nfinal.

3.  Explain why both the electron affinity and the ionization energy of Cl are greater than the corresponding quantities for S.

4.  Electrons may be ejected from the surface of Mo by photons of 274 nm or less. What is the work function of Mo? What is the maximum kinetic energy of electrons ejected from Mo by 100 nm photons? What is the speed of the electrons ejected by 100 nm photons?

5.  Calculate the energy required to remove the electron from the ground states of the following ions: He+, Li2+ and Be3+.

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