Ducksters
Ducksters: Kids Science: Solid, Liquid, Gas
Kid's learn about the science of states of matter. Solids, liquids, gases, and even plasma.
Channel 4 Learning
4 L: Science Essentials: Material World
Learn about topics related to the material world. Each topic includes facts, a glossary, an interactive quiz, printable worksheets, an image bank, and web links.