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.

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

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

How does a flashlight work? Kids will make a complete circuit and explore how voltage contributes to brightness with this science fair project idea.

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.

Teach your first grade scientist the difference between liquids and solids using maple syrup.

While your cells are much too small to see without a microscope, you can create the look of a cell in your very own home with just an egg and vinegar!

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.

Challenge your learner to design and build a city of their own in this creative engineering activity.

This science fair project idea teaches how the gases and pollution in the air affect the earth's atmosphere temperature.

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.

Explore scientific concepts with this experiment that introduces kids to the scientific method!

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

What is persistence of vision? With this hands-on science fair project idea, students will demonstrate this cool and dramatic phenomenon in their own classroom.

In this exciting design challenge, your child will use design thinking skills to create a mixture that can inflate a balloon.

Did you even wonder why some rocks are round and smooth while others are broken up into small pieces?

How do icicles form and what do they look like? Do this free science fair project and watch the formation of icicles occur right before your eyes.

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?

What do ants eat? Kids find out by observing a colony of ants in this cool zoology science fair project for 4th grade.

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

What causes dilated pupils? Young scientists will find out by applying what they already know about changes in pupil size and making models of the pupil.