General

• The Greek Concept of Atomos: The Indivisible Atom - John L. Park
• Atomic Structure Timeline - Lee Buescher
• Modern Theory of Atomic Structure - Friends School Chemistry
• Atomic Structure from Democritus to Dalton - John L. Park
• John Dalton (1766-1844): The Father of the Chemical Atomic Theory - John L. Park
• A Biography of John Dalton
  

• J.J. Thomson's discovery of the electron - John L. Park
• Atomic Theory I - Visionlearning
• The Thompson Model of the Atom - John L. Park
• Determination of the Charge on the Electron - John L. Park
• Excerpts from Thomson's Nobel prize address

• Wave-Particle Duality
• Atomic Structure - Anthony Carpi
• Atomic Structure - Developed by The Shodor Education Foundation, Inc.
• Structure of the Atom - NYU
• Atomic Structure Concepts - HyperPhysics
• Random Online Quizzes

• A Periodic Table Site -  with charts, quizzes and a great deal of information.
• A Quick Look at the History of the Periodic Table - PeriodicTable.com
• A Brief History of the Development of the Periodic Table - Western Oregon University
• WebElements Periodic Table
• Chemicool Periodic Table
• The Periodic Table of Elements - American Institute of Physics
• A comic book Periodic Table

• Nuclear Notation - HyperPhysics
• Isotope Notation - Physics 2000
• Atoms and Molecules 

• Random Online Quizzes
• Electron Configuration - Wikipedia
• Electron Notation Review - Sciencegeek
• Electron Configuration - Michael Blaber
• Electron Configuration Applet - Lectureonline

• Random Online Quizzes