This classic children's game demonstrates how sound travels through air vs. through a solid.

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.

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

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

In this sound experiment children listen for differences as they tap on a bag of air, a bag of water, and a wooden block held up to their ears.

This classic children's game-connecting two cups with a string-demonstrates sound's ability to travel through air vs through a solid.

Science fair project that examines what causes thunder and why a thunderclap sounds so loud. How is lightening related to the creation of sound waves?

Science fair project that examines condensation and the conditions needed in order for dew to form.

This science fair project idea determines if the size of the parachute will change the rate at which an object falls.

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

Science fair project that examines the different types of precipitation, evaluates the density of snow and calculates the ratio of snow-to-liquid.

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

This science fair project teaches students about wilting and browning of salad greens.

How does the size of a vibrating surface affect the pitch of a drum? Learn about drum size and pitch with this easy science fair project idea.

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

The goal of this evaporation experiment is to learn about how different external conditions affect drying time.

This science experiment examines the role of fat in food, especially in making bread rise and whipping cream.

What is surface tension? Kids will discover how water-skating insects use surface tension to keep from sinking by making a model water walker.

Do you think you can blow down a sand castle with a mighty wind? Find out which material stands up best to erosion in this erosion experiment.

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

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

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.

How do animals keep warm? In this experiment, find out whether fat insulation resists cold temperatures and learn how this works in the animal kingdom.

This science fair project idea investigates how the shape of an object affects drag.

With this cool floating rocks project, your child will get some hands-on experience with buoyancy and learn why certain rocks like pumice are able to float.

When you rub a balloon on your head, your hair stands up; but is that true for everyone? Does hair color affect static electricity?

In this science fair project, kids measure how weather conditions affect how fast a puddle evaporates.

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?

In this cool engineering science fair project, kids learn how to build Hero's engine: an enlightening example of Newton's third law.