There is a website created by John Geldar, et al. at Oklahoma State. I was shown this site at the AP institute I attended last Summer. It has been NSF funded and is a great simulation site for looking at particle models of reactions, reaction kinetics, equilibrium etc. Very good for advanced level chemistry as well. You simply have to register your name (nothing else). That is to keep the federal flow of money coming in with proof it is being used. The link is below. http://genchem1.chem.okstate.edu/CCLI/Startup.html Brad Cline Science Dept. Chair AP Chemistry & Physics Teacher Goddard High School 2500 S 199th St West Goddard, KS 67052 316-794-41000 x2808 bcline@xxxxxxxxxxxxxx CONFIDENTIALITY NOTE: The information contained in this memo is privileged and confidential information intended only for the use of the individuals named. If the reader of this message is not the intended recipient you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited.