American Association for the Advancement of Science
Aaas: Project 2061: Topic: Atoms, Molecules, and States of Matter
[Free Registration/Login Required] Create a science test that checks for student understanding in science, for common misconceptions, as well as for correct ideas. This is a list of key ideas related to Atoms, Molecules, and States of...
University of Virginia
University of Virginia: Indirect Measurement
This site contains an exercise that teaches about indirect measurements, used in this case to describe objects we cannot see.