Or the mozilla dev center, W3Schools has some issues (http://w3fools.com/)
Re:Periodic Table of the (HTML5) Elements
by underwater on Sunday April 03, 2011 @06:17AM
(#2402319)
Creator here. That's been on my todo list for a while. MDC might be a good replacement.
One request: please switch from W3Schools to the official W3C spec for the "more-info" link.