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

Kids will create their own version of Richard Feynman's rubber band heat engine to learn about thermodynamics with this cool science fair project idea.

Why does honey crystallize? This science fair project project answers this question and identifies the variable that makes this sweet solute crystallize faster.

What animals are most popular? This project affords practice in data-collection, record-keeping and data-analysis through the investigation of this question.

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

Kids make a paperclip perform an act of magnetic levitation and test how effective various materials are at magnetic shielding in this science fair project.

Science fair project which measures the shadow cast by a meter stick at various times in order to predict the circumference of the earth.

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

Learn how to make an anemometer with step-by-step instructions in this cool science fair project idea for 4th grade.

What does a raindrop look like when it splashes on the ground? Is each raindrop unique like snowflakes? Find out how raindrop size varies in this experiment.

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

How clean is the air we breathe? The answer might surprise you. Learn how to investigate local air quality with this cool science fair project.

What is persistence of vision? With this hands-on science fair project idea, students will demonstrate this cool and dramatic phenomenon in their own classroom.

This science fair project idea explores plant growth from a bulb, root, and a stem and investigates asexual plant reproduction.

The objective of this science fair project is to examine the basic principles of air pressure using simple materials like a balloon, straw and string.

examine how passive solar heating works, measure temperature in a parked car on a sunny day. ways to use passive solar heating as an alternative, energy

Soil and energy don't go together, right? That would be as bizarre as a pairing of peanut butter and marshmallows! Well, actually...

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

This science fair project idea investigates how the height at which a pendulum is released affects the length of time it continues.

Science fair project that determines whether cooling eggs helps them be peeled more easily. Compare the time it took to peel each egg.

Do you think you could walk around upside down -- with your feet in the air and your head on the ground?

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?

Construct and experiment with a periscope using reflected light rays to gather an image.

Science fair project which measures whether tsunamis are more destructive when they are caused by an earthquake or by a meteor.

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 science project uses Mohsâ Hardness Test to show kids how to compare the hardness of different types of minerals.

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

The goal of this science fair project is to demonstrate different ways to generate static electricity and record its effects.

In this science experiment, observe convection currents forming and learn about how heat energy moves in liquids from hot to cooler areas through convection.

Future engineers, unite! Discover how to keep a sandcastleâs bridge from falling into the moat.