This is a quick, easy science fair project that conveys the idea of density to upper elementary students.

Get your hands on a concoction that breaks the rules about what's a solid and what's a liquid.

Kids will conduct a cool limewater carbon dioxide test that can be performed with common household materials to learn about the chemistry of this common gas.

How does rust form? Kids will learn about the roles oxygen, water, and electrons play in rust chemistry in this cool science fair project idea.