This is an interactive periodic table that shows valence electron, densities, melting points, and other various characteristics of elements on the periodic table. Also, when you click on an element, it takes you to the wikipedia page for the element.

This is a great resource site that is similar to Diigo. Many of the sources deal with technology in the classroom as well as science.

This is a great resource that allows teachers or students to make engaging presentations or slideshows. There are also many other applications that can be made on this site, such as an interactive timeline or comics and cartoons.

This site has many tutorials and lesson plan starters related to chemistry concepts and topics. There are many great ideas that are explored in this site that can be used in introductory and advanced level chemistry classes

This is a site from the University of Illinois that shows various chemistry demonstrations that are performed in the general chemistry lectures. It also shows how to set up these demonstrations.