Air invisible; it doesn't make sounds; you can't pick it up and throw it. So how do we know it exists? Help your second grade scientist figure it out.

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

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 sound experiment children listen for differences as they tap on a bag of air, a bag of water, and a wooden block held up to their ears.

How does a kazoo, the strings of a guitar, or the speaker of a radio make sound? The purpose of this science fair project is to show how vibration makes sound.

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

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!

Do different types of oil mix or stack? Find out in this science fair project idea!

Test your friends to find out if you can replicate the placebo effect's incredible results.

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

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

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.

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

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

In this fun design challenge, your child will get creative with making structures out of toothpicks and gumdrop candies.

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

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

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

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

Your child might have noticed how bubbles quickly lose their colors and pop. Check out this creative way to make those bubbles last longer.

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.

Develop your child's mathematical and engineering skills with this fun building brick challenge. In this activity, your learner will be challenged to create a boat out of building bricks.

In this Halloween-themed activity, young learners will find out what happens when they mix two household items together to create a surprising chemical reaction.

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 activity, your child will be challenged to build a tall tower out of building bricks! The instructions include questions prompts to guide students through the design challenge.

Do you think you can blow down a sand castle with a mighty wind? Find out which material stands up best to erosion in this erosion experiment.

In this activity, your student will be invited to build a chair out of building blocks that is designed to meet the specific size and shape of a small doll or toy figure.

Before Twitter, birds were the ones tweeting, not humans. Have your child discover the magical sounds of nature while recording birds around his neighborhood!

Using a toy race car kids create a visual model of the Doppler Effect.

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.