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.

Did you know a mouse eats almost fifty times as much as a cow? Find out how and test out the strange science with your friends!

Check out this cool science fair project idea that models the behavior of the cold desert plants: xerophytes and halophytes.

Use pepper and soap to discover some fun facts about the properties of water.

Do earthworms like moisture or darkness? Find out as we explore the relationship between earthworms and light.

Find out whether soil amendments can improve soil conditions and help you grow a bigger beanstalk in this ecology experiment!

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 science fair projects, students will grow out the bacteria that collect on air conditioner filters.

Learn how to make a food pyramid with animals in a a coniferous forest ecosystem around your home.

What is elasticity? Students will investigate how this concept applies to bouncing ball physics by testing the bounces of balls made out of different materials.

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

In this project, learn about animal vision and different kinds of eyes: ocelli, compound eyes, and camera eyes. Find out what a jellyfish or grasshopper sees!

Start your toy engines -- this is going to be a fast and friction-filled race!

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

This cool science fair project teaches kids about temperature, density and buoyancy using balloons that float with normal air. No helium required!

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.

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

This science fair project idea investigates the difference in reaction times between boys and girls.

Certain fruits can change gelatinâs ability to set. In this experiment, kids will discover what happens when gelatin meets pineapple enzyme.

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

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.

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

Will potatoes spud or sprout faster in dry, dark, or cold conditions? Find out in this science fair project idea!

Tired of gum with flavor that lasts for just a couple of minute? Put gum to the test with this chewy science experiment!

This science fair project idea investigates which objects float and sink in honey, water, and oil.

This science fair project looks one of the most important factors affecting seed germination: water. A fun and easy plant biology experiment for 3rd graders.

It's rhyme time! With this science fair project idea, your child will find out which words can be considered easy rhyming words, and why.

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.

This science project uses Mohsâ Hardness Test to show kids how to compare the hardness of different types of minerals.