Session Overview
| Modules | Structure of the Atom |
| Concepts | Bohr-Sommerfeld model and multi-electron atoms, quantum numbers (n, l, m, s), Balmer and Pfund series, Rydberg equation, Stern-Gerlach experiment |
| Keywords | angstrom, wavelength, wave number, electron-volt, electron shell, electron subshell, quantum numbers, James Franck, Heinrich Hertz, Albert Michelson, Edward Morley, Pieter Zeeman, Hendrik Lorentz, emission line splitting, Arnold Sommerfeld, Bohr-Sommerfeld model, multi-electron atom, Johannes Kepler, Niels Bohr, Otto Stern, Walter Gerlach, Rydberg equation |
| Chemical Substances | hydrogen (H), helium (He), mercury (Hg) |
| Applications | photodetectors |
Prerequisites
Before starting this session, you should be familiar with:
Looking Ahead
Prof. Sadoway discusses particle-wave duality (Session 6).
Learning Objectives
After completing this session, you should be able to:
- Describe the structure of shells and subshells in multi-electron atoms, and relate them to the observed emission spectra.
- Explain the Bohr-Sommerfeld model.
- For an electron in a given subshell, determine the quantum numbers, and explain your answer.
- Use the Rydberg equation to calculate the values of hydrogen spectral lines.
Reading
Archived Lecture Notes #1 (PDF), Section 3
| Book Chapters | Topics |
|---|---|
| [Saylor] 6.5, "Atomic Orbitals and Their Energies." | Wave functions; quantum numbers; orbital shapes; orbital energies; effective nuclear charges |
| [Saylor] 6.6, "Building Up the Periodic Table." | Electron spin: the fourth quantum number; the Pauli principle; electron configurations of the elements |
Lecture Video
> Download from iTunes U (MP4 - 221MB)
> Download from Internet Archive (MP4 - 221MB)
Resources
Lecture Summary
In this lecture, Prof. Sadoway discusses the following topics:
- Visible light
- Bohr's model for hydrogen (single-electron system)
- Limitations of Bohr's model
- Sommerfeld's proposal of "elliptical shape" for electron orbitals
- Quantum numbers: n, l, m, s
- Stern-Gerlach experiment
- Franck & Hertz experiment
- Gas discharge tube
- Existence of a threshold energy for exciting electrons in Hg atoms
Homework
Textbook Problems
| [Saylor] Sections | Conceptual | Numerical |
|---|---|---|
| [Saylor] 6.5, "Atomic Orbitals and Their Energies." | none | 1, 3, 5, 6, 7 |
For Further Study
Supplemental Readings
Michelson, Albert A. Studies in Optics. Chicago, IL: University of Chicago Press, 1927.
Sommerfeld, Arnold. Atomic Structure and Spectral Lines. New York, NY: E.P. Dutton, 1931.
Sommerfeld, Arnold. Optics. New York, NY: Academic Press, 1964.
Dick, Harold G. The Golden Age of the Great Passenger Airships, Graf Zeppelin and Hindenburg. Washington, DC: Smithsonian Institution Press, 1985. ISBN: 9781560982197.
People
Niels Bohr - 1922 Nobel Prize in Physics
Max Planck - 1918 Nobel Prize in Physics
Otto Stern - 1943 Nobel Prize in Physics
James Franck, Gustav Hertz - 1925 Nobel Prize in Physics
Albert Michelson - 1907 Nobel Prize in Physics
Pieter Zeeman, Hendrik Lorentz - 1902 Nobel Prize in Physics
Other OCW and OER Content
| Content | Provider | Level | Notes |
|---|---|---|---|
| 5.111 Principles of Chemical Science | MIT OpenCourseWare | Undergraduate (first-year) | Lecture 6: Hydrogen Atom Wavefunctions |
| Atomic Structure, The Hydrogen Atom | HyperPhysics | High school |