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

In this cool science experiment, learn about magnetism and poles, and test magnet strength to find out if two magnets are twice as strong as one.

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

This project compares the strength of one, two, and three-ply toilet paper.

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

In this science fair project, young children discover what happens when two fluids that have different densities get together.

This science fair project creates a visual model of whatâs happening to sound waves as a car approaches and then leaves.

In this experiment, your child will create two compost bins and see if he can determine what attracts fruit flies.

Milk is made of water and fat; but how can you separate the two? Find out in this color changing milk experiment.

In this popcorn experiment, students can explore how two things made out of the same material can have very different appearances and densities.

Young scientists will investigate people's preferences for saltiness, and make some inferences about genetics and diet.

What's the relationship between temperature, air humidity and static electricity? Kids will find out with this free static electricity science fair project.

In this fun science fair project, make two different scale models of our solar system using Astronomical Units and planets' relative size!

What's the difference between a microwave and an oven? Use mashed potatoes to explore which kitchen appliance does a better job at keeping food warm.

Using an empty tennis ball can and a swimming pool, you will determine if it's possible to have a conversation under water.

What causes the seasons to change? Kids find out by modeling the earth's tilt using a globe, flashlight and graph paper in this cool science fair project idea.

Most people assume that cold water freezes more quickly, but could that be false? Does hot water freeze faster than cold water? Let's find out!

In this science fair project, we'll use a liquid crystal thermometer to find out whether exercising makes a difference in people's temperature.

Learn about magnifying glasses, concave lenses and inverted images by sending rays of light through a magnifying glass in this cool science fair project!

In this experiment, students will create their own version of coquina, a sedimentary rock thatâs formed by seashells and sand, cemented by seawater minerals.

Magnets vary in strength. Have your young scientist figure out which kind of magnet is the strongest when you have him conduct this attractive experiment.

In this science fair project, students create their own miniature salt flats at home.

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

The objective of this science fair project is to investigate salt water density.

Why doesn't the ocean freeze? Students answer this question by simulating the chemical composition and temperature of arctic waters in their own home.

Did you ever add salt to pasta? Did it help cook the pasta faster? If not, find out in this science fair project idea.

Kids will make a beautiful rainbow in a jar and learn what enables different types of liquids to remain distinct in separate layers.

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.

Do you think heat can affect a plant's growth rate?

This science project teaches young students about germs, bacteria, and the importance of washing their hands. Students will test what is the best way to wash.