Here's a resource ideal for independent learners who need extra reinforcement or would like to work ahead. These textbook chapters and practice problems cover many basic physics concepts, starting with potential and kinetic energy and...

Explains the Law of Conservation of Mass, or Law of Conservation of Matter, and gives two examples for it.

Explore the concept of matter in this Spanish-language encyclopedia entry. This site features the properties of matter, the Law of Conservation of Matter, and other important features of matter.

This Homewood City Schools site has an outline form and contains lots of information about the classification and composition of matter. Some of the topics covered are matter and temperature, changes in state, composition of matter, and...

This site has a definition and properties of Leptons, the "Basic building blocks of matter." There are links to table of properties and more information.

Mercury in the geochemical cycle ultimately affects the food chain. Learn about this and its effect on the Everglades.

In addition to quick facts, the Brookfield Zoo presents information on the social and eatings habits, appearance, conservation matters, and other characteristics of the black-footed cat.