Using a toy race car kids create a visual model of the Doppler Effect.

Step into the fantastic world of colors with a project that explores what shade you -- and your friends -- like best.

Take a closer look at your furry friend (or the furry friend of a neighbor -- with permission) to discover if communication exists between cats and humans.

Kids construct a single fixed pulley system to learn how pulleys can make work easier in this cool physics and engineering science fair project idea.

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 science fair project idea determines what household items are good conductors of electricity.

This science fair project idea determines what household items are good conductors of electricity.

Is it possible to trick the forces of nature that make your bubbles round to create a square bubble?

This science fair project idea demonstrates how air resistance contributes to denser objects falling faster than less dense objects.

Most people assume that cold water freezes more quickly, but could that be false? Does hot water freeze faster than cold water? Let's find out!

Test your friends to find out if you can replicate the placebo effect's incredible results.

This is a quick, easy science fair project that conveys the idea of density to preschool and early elementary children.

This science fair project idea determines if crystals will absorb food dye and if colors will mix by the process of diffusion.

Check out this cool science project idea to learn about rocks and explore the cycles of formation, breakdown, and reformation of rocks in the Earth's crust.

How do organic materials become soil? This science experiment measures what materials biodegrade.

It's rhyme time! With this science fair project idea, your child will find out which words can be considered easy rhyming words, and why.

This science fair project idea explores how enzyme inhibitors, active sites, non-competitive enzyme inhibitors, and substrates work.

This science fair project teaches students about wilting and browning of salad greens.

This science experiment examines the role of fat in food, especially in making bread rise and whipping cream.

Here is a fun middle school science project on factors affecting solubility. Learn how dissolved solids can "crash out" to form crystals when conditions change.

What is a compound microscope? Kids find out by making one of their own in this cool science fair project.

Crayons aren't just good for creating colorful masterpieces -- they're also great for science!

This science fair project idea investigates how optical distances change the apparent size of an object as seen through a magnifying lens.

The moon doesn't produce its own light, so why can we see it shining in the sky? Learn about reflection and planetshine in this fun and easy science project!

Young scientists will investigate people's preferences for saltiness, and make some inferences about genetics and diet.

Plants and light seem to be good buddies, but how far does the friendship really go?

Find the North Star, and measure your latitude! The purpose of this science fair project is to find latitude and learn about geographic locations.

Gather some friends for a bubbly soda taste test do determine calories' role in your favorite drinks.

Science fair project that examines albedo, and how this information is applied in the design of cars, sportswear, and other items. Which colors reflect light?

Science fair project that examines the behavior of water and gravel in creek beds and the formation of sedimentary rocks.