Soil is made up of different layers. How far down do you need to dig to find the soil horizon, or the place where bits of leaves and branches become soil?

How good are humans at sound localization? Kids can try this cool science fair project idea to see how good their friends are at judging sound direction.

What are the effects of colored light on plant growth? Explore plant behavior in this cool botany science fair project and learn about phototropism!

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

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

Learn about magnifying glasses, concave lenses and inverted images by sending rays of light through a magnifying glass in this cool science fair project!

In this fun science experiment, kids will determine the best method for ripening avocados and discover the cool chemical reaction that makes this possible.

What is a wedge? Kids find out by experimenting with different wedges in this simple science fair project idea.

Get down to the rubber with this science project that tests the effectiveness of different types of erasers.

Science fair project in which you will learn more about the natural world by preserving and identifying different animal tracks.

This cool science fair project teaches kids about temperature, density and buoyancy using balloons that float with normal air. No helium required!

Did you know your body is full of simple machines? This project looks at one of the third-class levers in the human body: your arm!

Science fair project which teaches you about the principles of physics within a vacuum by creating a vacuum chamber.

In this fun science project, learn about what happens to cut fruit and experiment with how to stop apples from turning brown.

Learn about the effect of artificial light on plant growth versus natural sunlight and delve into some biology and botany concepts in this science project.

In this enlightening transpiration experiment, kids will explore how the loss of water from plants through transpiration contributes to the water cycle.

In this simple circular motion experiment, you'll observe tangential velocity and learn about how acceleration and centripetal force affect an object.

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.

This science fair project explains the process of how the lungs expand and contract with the help of the diaphragm.

This science fair project idea provides evidence that air is everywhere and takes up space.

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

Help your second grader observe the phases of the moon, and then let the fun loose: he'll get to chart his observations with marshmallows!

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

In this activity, your child will transform an egg into a glowing, bouncy "ball" that they can play with.

Create safe lightning for kids! They'll learn how to make lightning at home with this fun science fair project idea illustrating static charges and grounding.

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 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.

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

This science fair project idea attempts to train a worm to complete a simple maze in order to find out if worms can learn and remember.