Links to many good web sites for K-12 science and math classes.
Waterworks is a great introduction to the physics of water and the mechanics of moving liquids.
Investigate fountains and create your own. Exploration fo the electron microscope and more. A large lesson plan storehouse is at this web site. This site includes complete lesson plans and instructions of several interesting labs suitable for 10 - 12 science classes. Some of these labs are applicable for various science courses including chemistry, physics, physical science, biology and earth science.