History Of The Periodic Table Of Elements

http://www.ausetute.com.au/pthistor.html

http://www.colorado.edu/physics/2000/periodic_table/index.html

Nifty Periodic Tables

http://www.colorado.edu/physics/2000/applets/a2.html

http://www.dartmouth.edu/~chemlab/info/resources/p_table/Periodic.html

http://www.lynchburg.net/hhs/chemistry/trends/?step=2

http://www.ptable.com/

9th Grade Physical Science: The Gas Laws

Cool virtual lab:

http://www.glencoe.com/sites/common_assets/science/virtual_labs/PS08/PS08.html