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

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

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

How can we describe the relationship of magnetic field strength vs. distance? Kids will find out with this free science fair project idea.

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

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

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.

Will storing cucumbers and tomatoes in the fridge destroy their unique flavors? Find out in this science fair project idea!

For this science fair project, kids will learn how to make a lemon battery. They can conduct this classic experiment using readily available materials.

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.

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

What do worms eat? Kids find out what kinds of rotting leaves and vegetables worms prefer in this cool compost science fair project.

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

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

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

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

These science fair experiments demonstrate the chemistry of rust and the oxidation process.

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.

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.

Learn about this simple machine and make a pulley of your own to use for fun science trials.

Science fair project idea that examines different physical characteristics of a chosen animal. Make educated guesses about evolution based on animal's form.

This project leads to an understanding that a whole may be built of smaller parts that fit and work together and provides an introduction to basic tools.

This project determines what category of person is most likely to be ticklish.

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.

Wiggly worms are known for staying buried in the soil, but how does that affect plants? Are earthworms and plant growth related?

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

This experiment challenges students to forecast the weather based on the surrounding areas' weather.

Stories change as you retell them. The objective of this science fair project is to demonstrate how information gets interpreted, distorted and changed.