CK-12 Foundation
Ck 12: The Quantum Mechanical Model
[Free Registration/Login may be required to access all resource tools.] In the following online tutorial students will calculate the wavelength, frequency, and energy of light using Planck's constant and the speed of light. They will...
Khan Academy
Khan Academy: The Quantum Mechanical Model of the Atom
An explanation using quantum mechanics to describe the atom.
Simon Fraser University
Chem1 Virtual Textbook: Movement of the Electron
Acting as a subtopic of the General Chemistry Virtual Textbook's section on Atoms and the Periodic Table, this site seeks to answer the question, "Why doesn't the electron fall into the nucleus?"