Resource for first semester chemistry students or those needing a refresher. Site includes a compound library, construction kits, calculators, simulators, and tutorials. Has not been updated since 2010.
Science.gov searches over 60 databases and over 2200 selected websites from 15 federal agencies, offering 200 million pages of authoritative U.S. government science information including research and development results. From home page, select "advanced search" and "Math, Physics & Chemistry" from the category options.