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

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

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

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

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

Be a chemist for a day and study the simple reaction between sugar and heat. Try heating sugar and see what happens!

What makes your shadow dance around all day? Let's play detective and find out why that sneaky shadow never stays in one place for long.

What animals are most popular? This project affords practice in data-collection, record-keeping and data-analysis through the investigation of this question.

In this science fair project, you'll make a "ghost" appear in a test tube, and learn about what happens when hot water and cold water interact.

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.

Science fair project that demonstrates the effect of detergent pollution on fresh water birds' ability to stay afloat.

Learn about the layers of the Earth and make a model! Create a earth layer book, cake, or clay diagram.

This project examines whether people's taste perception is influenced by what they see.

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

People have favorite flavors, but what about ants? Which ant food is the most popular?

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

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

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

What's the science behind those out-of-sight roots? Find out if you can trick roots into growing in different directions.

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

This project demonstrates the correspondence between the volume of water displaced by a submerged object and the volume of the object displacing it.

Test whether plants can grow without sunlight and water.

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

The objective of this science project was to build a model of a volcano and observe reaction between different substances, including baking soda and vinegar.

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

This science experiment has students test whether a snail moves faster on concrete or dirt.

Find out whether we can create motion in a dish and as a result, create a wonderful and colorful show.

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.

Check out this fun science fair project idea for 1st grade: a solar eclipse model that demonstrates total, partial, and annular solar eclipses.

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