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.

Experiment with buoyancy to learn how a submarine rises and sinks in this classic science experiment.

Demonstrate the relationship between mass, volume and density. Measure displaced water, and weigh object to calculate mass and density.

Here's an easy experiment that lets your first grader practice the scientific method, while watching a caterpillar eat.

Determine whether butterflies like to drink sugar water, salt water, or plain water.

Compare the whitening abilities of four different brands of whitening toothpaste to see which one whitens the fastest and which one whitens the most.

This is a fantastic and easy science experiment where kids will learn about elasticity by testing how high bouncy balls of different materials can bounce.

Uh-oh! Is that a pill sitting on the counter or a piece of candy?

In this experiment you observe and determine how well your cat uses his whiskers to navigate through a maze.

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.

The objective of this science fair project is to study the photosynthesis process and demonstrate the important role that leaves play in the process.

Evaluate the ability of a biodegradable dish detergent to increase the penetration of water in hydrophobic soils.

Determine whether a hot liquid cools off faster when liquid is added before or after a two minute wait.

In this science fair project, young children notice and track changes in trees throughout the year.

Polymers remove oil from contaminated waters. The purpose of this science project is to test the effectiveness of a polymer in cleaning up an oil spill.

Kids will love making sugar crystals in this sugar crystal science fair project which teaches important chemistry concepts like saturation and solubility.

This project analyzes people's emotional responses to images in painting vs similar images in photographs.

Sink or swim? Calculate the density of various fruits and vegetables using water and a kitchen scale.

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

Explore the concept of receptive fields and why different parts of our body have different levels of sensitivity.

Thermometers are how we measure temperature, and we've all heard the terms "centigrade" and "Fahrenheit" tossed around, but what do they really mean?

Kids will enjoy this cool demonstration of Newton's Third Law and the conservation of linear momentum.

How does water pressure change with depth? Kids learn how pressure works underwater with this cool and easy demo.

Science fair project which determines whether the size or the thickness of a piece of paper has an effect on how many times it can be folded in half.

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

Have you ever seen fruit decay? Find out if a fruit will rot faster if you open it versus leaving it untouched!

In this science fair project, apply the principles of leverage and force by building six simple machines designed to set weights in motion.

Observe corn seed germination to learn about dicots and monocots and how plants grow from seeds to seedlings to full-grown plants!

Looking for a project on machines? Get a fun elementary school science fair project idea to design a compound machine using your knowledge of simple machines.