Relevant links at Khan Academy, organized by Unit.
1 Khan Atomic Structure and Electron Configurations — Khan academy lessons on atomic structure and electrons
1 Khan Intro to Atom — Khan Academy introductory lessons on the atom and elements
1 Khan Periodic Table and trends — Khan academy lessons on periodic table, periodic trends and bonding
2 - 3 Khan Compounds and Reactions — Khan academy lessons on compounds, chemical reactions, and stoichiometry