Watch different types of molecules form a solid, liquid, or gas. Add or remove heat and watch the phase change. Change the temperature or volume of a container and see a pressure-temperature diagram respond in real time. Relate the...

This interactive allows you to explore the effect that temperature and pressure have on the changes in the states of matter. You can test these variables on carbon dioxide, hydrogen and water.

Discover the concept that energy transfer and molecular motion cause the change in state from a solid to a liquid. Also compare state changes of water to the state changes of other substances.

Learn about matter, its three states, changes of state, how matter behaves, and physical and chemical changes in matter.

The Beatles' first visit to the United States was in 1964. Clever publicity agents arranged a meeting for the band with Cassius Clay. He was training for the bout that would make him heavyweight boxing champion. The result was a...