Other
Iun: Modern Atomic Theory
This is an excellent site with information on the discovery of the atom and the different models. Includes a sample question and answer using Planck's constant.
Boise State University
Boise State University: Atoms: A Virtual Field Trip Through Time and Space
Learn about the models of the atom that have been proposed throughout history. Presents Democritus, John Dalton, J.J. Thomson, Ernest Rutherford, Niels Bohr, and the modern theory of the atom. Sections are accompanied by journal...