PTable.com offers an interactive, online-based periodic table of elements (also known as the Mendeleev table). The site is accessible without requiring a Flash plugin; it shows comprehensive information about the elements, their isotopes, their orbitals, as well as their state at different temperatures.
The table is one of the most interactive and comprehensive versions that we’ve seen until now on the web, and this fact reflects itself in its traffic. Compete.com shows that the site managed to consistently attract at least 100’000 monthly unique visitors in the last year.
The service is ad-supported but free of charge. All the features are available to regular users without requiring any sort of sign-up or any form of payment.
The table has been created by Michael Dayah from Knoxville, Tennessee, United States. The site has a long history behind it; the first version appeared in 1997, one year before Google. However the first version was pretty much a static page; as the web evolved, additional features got added to the page. Interactivity was radically enhanced throughout the summer of 2007 and improvements continue into the present day.