Test out the pH levels of soil in your backyard versus soil in more wild environments to solve this science case.

This science fair project demonstrates the magic of arches by challenging students to stack telephone books on top of eggs without breaking them.

Science fair project that compares the biodiversity of fungi in different ecosystems by identifying species of fungi.

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

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

The objective of this science fair project is to set up a compost bin to convert food scraps and organic waste.

This science fair project idea investigates if webbed feet help a duck (and others) swim.

This project examines what types of objects burn and which burn faster and cleaner.

Learn about the power of exponents. The objective of this science fair project is to explore and understand how exponents are used.

Learn how to make a hygrometer to measure relative humidity in this project. Make a sling psychrometer hygrometer with gauze, thermometers, and a bottle.

Would it hurt to skip brushing your teeth just this once? Let's find out by seeing which foods produce the most mouth bacteria.

This science fair project idea explores whether cats can be trained in the same way that dogs can.

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.

What do ants eat? Kids find out by observing a colony of ants in this cool zoology science fair project for 4th grade.

This science fair project idea explores alcoholic fermentation at work by making your own soda.

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

Science fair project which tests various sedimentary, igneous and metamorphic rocks to find out whether one rock family is stronger than the others.

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.

Kids will build a turtle habitat in order to observe the climate preferences of this cold-blooded reptile.

In this science fair projects, students will grow out the bacteria that collect on air conditioner filters.

Science fair project that identifies the differences between soils from different environments and attempts to figure out why those differences exist.

In this science fair project, students examine under what conditions individual plants release seeds and how far the seeds are released.

Kids will discover the meat science behind the meat they eat, and find out how to use safe chemistry to make meat more tender.

With this science fair idea, little scientists will gain valuable insights into the physics behind throwing a baseball.

This science fair project examines which fruits and/or vegetables will ripen prematurely when placed with ripe apples.

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?

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.

In this science fair project, students make their own rain gauge to measure rainfall.

Saturn is the ringed planet in our solar system, a gas giant with rings made of ice and dust. Let's make a cool scale model with an old CD and some glitter!

This fun science fair project idea helps students learn how acid rains are formed and explore how acid rain damages the environment.