Middle School Chemistry
A totally free teaching resouce that helps you to investigate the world of atoms and molecules.
At middleschoolchemistry.com, you can view and download fully developed lesson plans that you can use to teach an entire middle school chemistry unit. Each activity, as well as the entire 610 page book, is available for free download in PDF format. The website also has a multimedia section, complete with molecular model animations and videos, and information on upcoming workshops based on the book.