In this air pressure science experiment with a balloon and a jar, children will use heat to create a partial vacuum and suck a balloon into a jar.

In this project children practice the scientific method while playing with puffy paint.

This science fair project idea determines if crystals will absorb food dye and if colors will mix by the process of diffusion.

This science fair project idea demonstrates how air resistance contributes to denser objects falling faster than less dense objects.

In this project, build an insect model that shows how the head, thorax, and abdomen fit together! Learn insect anatomy by constructing a paper mache critter.

Is it a square or a circle? See if you can trick your friends with this zany science project!

This science fair project idea investigates if fats add to the flavor of food.

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

In this experiment you will replicate the mummification process by making a hot dog mummy.

Do plants get crowded? Have your curious kid investigate how plants respond if they're forced to grow together in a confined space.

This project explores whether plants can live and grow when "watered" with juice, soda, or milk.

This science fair project idea demonstrates that plants give off water.

In this science fair experiment, children demonstrate the relationship between the amount of stuff and the amount of pressure in a closed system.

Discover whether cold or hot water from the faucet will boil faster on the stove.

This science fair project teaches about mold. Students will test different foods to see which grow mold the fastest.

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

This experiment has students record rat behavior to learn about the benefits of rats and research rat myths throughout history.

Are you ready to be a detective for science? Then get out your magnifying glass and start studying fingerprints!

In this free science fair project idea, we learn about surface tension and how it can support mass—in this case, a floating paper clip.

Kids will learn how to make a thermometer to to explore liquid density in this great science fair project. Which liquids are affected by temperature the most?

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

This science experiment tests why guacamole goes brown and if leaving the pit in will stop guacamole from turning brown.

How do organic materials become soil? This science experiment measures what materials biodegrade.

Step into the fantastic world of colors with a project that explores what shade you -- and your friends -- like best.

Can a horse lead itself to the carrot? Train your horse with carrots and boxes and test horse memory in this fun zoology science fair project.

Kids construct a single fixed pulley system to learn how pulleys can make work easier in this cool physics and engineering science fair project idea.

Take a closer look at your furry friend (or the furry friend of a neighbor -- with permission) to discover if communication exists between cats and humans.

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.

Which music genres have the fastest tempos? The slowest? This experiment determines if there's a relationship between beats per minute in a song and its genre.

In this science fair project, students discover how sedimentary layers form as sediments like mud, silt and sand settle over time.