This science fair project idea produces varying pitches of sound.

This science fair project idea experiments with spinning color wheels and optical illusions.

This science fair project idea produces sounds by creating vibrations using different objects.

In this science fair project, kids start a chemical reaction that will make a balloon inflate itself!

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

This science fair project idea explores whether talking to a plant will help it grow.

This science fair project idea investigates which objects float and sink in honey, water, and oil.

This science fair project idea explores the relationship between oil and water in terms of density as well as hydrophilic/hydrophobic compounds.

In this free science fair project, learn how to separate salt from water using heat. A great science project for elementary school kids.

In this fun science fair project idea learn about universal solvents and solutes and find out the solubility of several common liquid substances.

The objective of this science fair project idea is to determine if sound travels best through the air, water or a solid.

Science fair project that examines what causes thunder and why a thunderclap sounds so loud. How is lightening related to the creation of sound waves?

This science fair project creates a visual model of whatâs happening to sound waves as a car approaches and then leaves.

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.

For this science fair project, kids will learn how to make a lemon battery. They can conduct this classic experiment using readily available materials.

Have your child build his own mini waterfall, and help him develop his planning, problem solving, and architectural skills.

What is elasticity? Students will investigate how this concept applies to bouncing ball physics by testing the bounces of balls made out of different materials.

Discover whether different amounts of water added into a wine glass will produce a different pitch when their fingers are rubbed along the rim.

Using an empty tennis ball can and a swimming pool, you will determine if it's possible to have a conversation under water.

This project demonstrates the correspondence between the volume of water displaced by a submerged object and the volume of the object displacing it.

Observe how your brain works while it is focused on one thing, and how it works while you are distracted by another thing.

How do mirrors work? What is light, and how does it travel? Explore light and reflection with your preschooler with these simple hands-on experiments.

This simple "how to make a water wheel" activity makes physics come alive for your child by demonstrating how different kinds of energy work.

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.

Try this chemistry experiment with your curious kid and get some "shocking" results!