In this science fair project, young children discover what happens when two fluids that have different densities get together.

How do we know that air exists when we can't see it, taste it, or touch it? Here's a classic experiment that will teach your kid some basics of aerodynamics!

How does a kazoo, the strings of a guitar, or the speaker of a radio make sound? The purpose of this science fair project is to show how vibration makes sound.

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

Experiment with buoyancy to learn how a submarine rises and sinks in this classic science experiment.

Start thinking about how the internet works by assembling an Ethernet cable of your own!

In this activity, you'll not only make your own bouncy balls at home, but your child will also learn how polymers are made.

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

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 science experiment, your child will test the strength of hollow structures in order to understand how strong bird bones really are.

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.

Check out this fun science fair project idea to learn about seismic waves and how fast they travel during an earthquake.

This classic children's game demonstrates how sound travels through air vs. through a solid.

In this cool science fair project, kids apply basic algebra to learn how to make a PVC pipe instrument while exploring concepts like frequency and resonance.

Create a homemade pair of sunglasses with colored lenses to see just how light and color affect our sight! Use this fun project to practice science!

How fast does light travel in different mediums? Kids conduct a cool refraction experiment in materials like water and air for this science fair project.

Has your kid noticed how much bigger the moon looks when it's low in the sky? Here's an activity you can do to show them that it's just an optical illusion.