Royal Society of Chemistry
Royal Society of Chemistry: Gridlocks: Level 2
A collection of grid puzzles that cover a wide variety of topics in intermediate high school chemistry. These are excellent for topic review and reinforcement. The puzzles can be played online and also downloaded as worksheets. Answers...
CK-12 Foundation
Ck 12: Flex Book Textbooks: Chemistry Second Edition
[Free Registration/Login may be required to access all resource tools.] A complete, web-based, multi-media textbook covering a wide variety of Chemistry concepts.