Other
Valley City Junior High's Water Research: Water Issues
This site talks about the nitrate and nitrogen forms that can be found and how to test for it. Includes illustrative diagrams and graphs.
Davidson College
Davidson College: Molecular Orbitals of Ammonia
A Java applet shows a molecular orbital representation of ammonia. When an orbital in the diagram is clicked on, the isosurface is shown. The orbitals for other molecules can be accessed through links at the bottom of the page.
Purdue University
Purdue University: Calcium Hydroxide Crystal Structure
A picture of the crystal structure of calcium hydroxide. Additional plug-in required.