This site helps students construct a model of the arrangement of water molecules when present as solid, liquid or gas. Includes background information, lesson plans, links to standards and assessment ideas.

Did you know the ancient Greeks first identified the three states of matter? Read about how the molecules differ in solids, liquids, gases, and plasma. View photographs and watch how the molecules move in each state. If you're really...

In this activity, students construct models of molecules using marshmallows and gum drops.

Atoms are very, very small. Atoms are so small that it is often said that there are as many atoms in a single grain of sand as there are grains of sand on all of the world's beaches - certainly a difficult thing to prove, but you get the...