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

This science fair project idea explores whether factors such as temperature and concentration affect the pH of a solution.

The objective of this science fair project is to experiment with balancing everyday objects and observing the the effects of gravity on materials.

Demonstrate how you can make your own compass using a magnetized needle. It also allows you to compare magnetic north and geographic north.

Can you plant the insect-attracting borage plant to increase the amount of beneficial insects in your garden? Find out in this experiment!

In this experiment, students find out what happens when a less-dense fluid interacts with a denser one, replicating the effect of cooler solid rock on magma.

How do animals keep warm? In this experiment, find out whether fat insulation resists cold temperatures and learn how this works in the animal kingdom.

With this cool floating rocks project, your child will get some hands-on experience with buoyancy and learn why certain rocks like pumice are able to float.

How does the size of a vibrating surface affect the pitch of a drum? Learn about drum size and pitch with this easy science fair project idea.

Learn about sound physics and do a survey experiment to explore the difference between sound and noise in this science project.

In this cool project, create a lighted, scale model of the different layers of the Sun, including the core, radiation and convection zones, and photosphere.

Science fair project that helps you better understand density by comparing the relative densities of cans of Coke and Diet Coke.

This science experiment tests whether warm or cold water works best in making cut flowers last longer.

How does a compass work? What's a magnetic field? Kids will build their own compass at home to find the answers in this great science fair project idea.

Learn how to make a ping pong ball anemometerâa device used to measure wind speedâin this free science fair project idea.

In this pinto bean germination experiment, you'll learn about how fertilizer aids in growing pinto beans into seedlings.

In this cool science experiment, learn about magnetism and poles, and test magnet strength to find out if two magnets are twice as strong as one.

Kids will learn how to show the direction of magnetic field lines and create a permanent model using iron filings in this great science fair project idea.

Start your toy engines -- this is going to be a fast and friction-filled race!

Science fair project which determines if plants really do need water to grow, or whether they just need to be kept wet.

Check out this fun and easy 4th grade science fair project idea that tests how gravity induces positive and negative geotropism (gravitropism) in bean plants.

This science fair project idea investigates how magnetism can defy the force of gravity.

Kids will learn how to measure the viscosity of liquids by making their own homemade viscometer in this great science fair project idea.

This fun science project helps to investigate how much water can a plant take up and release in a certain period of time through the process of transpiration.

How does smell affect taste? Ready your taste buds--in this project, you'll gather some test subjects and do a taste test to see how much smell affects taste.

How can we describe the relationship of magnetic field strength vs. distance? Kids will find out with this free science fair project idea.

What keeps a an item cooler, polymer crystals or ice? Find out in this cool science experiment!

This simple heat transfer experiment is a great introduction to the concepts of heat transfer and conduction.

Kids will learn how to make a steam powered rocket boat, also called a putt putt boat or a pop pop boat, in this great science fair project for 4th graders.

This project explores whether nails, toothpicks, straws, or pen nibs are best for applying ink to paper.