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

This science fair project examines how seeds hitchhike on animals and clothing.

Determine whether butterflies like to drink sugar water, salt water, or plain water.

The objective of this science fair project is to observe the differences in heat absorption for darker colors vs. lighter colors.

Excite your fourth grader by recreating ancient Viking myths. This miniature longboat will explore the principle of water molecules expanding when heated.

Along with being an interesting science activity, dehydrated strawberries are also tasty â and healthy!

This science fair project teaches kids experimental design and how to test if subjects can really sense if they are being watched.

Make some easy homemade yogurt with your young scientist, and see what a few 'live' bacteria can do in the right conditions!

What does a raindrop look like when it splashes on the ground? Is each raindrop unique like snowflakes? Find out how raindrop size varies in this experiment.

Grow potatoes in a plastic bag—easy to grow and harvest, and yummy to eat!

Free science fair project idea that examines the differences between cats and dogs. Analyze objective qualities rather than subjective ones.

Have your child build a model of a coral polyp, one of the tiny animals that composes a coral reef.

This science fair project investigates why the number of visible stars changes from place to place.

Chemistry isn't just incredible ... sometimes its edible! These crystal lollipops are a delicious introduction to chemistry concepts.

Prove that the Earth is not flat. The objective of this science fair project is to measure the angle of the sun and calculate the circumference of the Earth.

The objective of this science fair project is to examine the basic principles of air pressure using simple materials like a balloon, straw and string.

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

This science fair project idea produces varying pitches of sound.

In this activity, you'll not only make your own bouncy balls at home, but your child will also learn how polymers are made.

Examine which metal conducts more heat by boiling water in 3 pans made of aluminum, copper, and stainless steel.

Get this cool science fair idea to explore how arctic tundra animals change their behavior and adapt to survive in long, cold winters.

Have your child kick off their summer vacation by making a miniature water slide!

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

This science fair project on testing water hardness is a great introduction to practical chemistry. Test and learn the difference between hard and soft water.

This science fair project idea explores how the shape of a boat affects its density and how much weight it can float.

Soil and energy don't go together, right? That would be as bizarre as a pairing of peanut butter and marshmallows! Well, actually...

This science fair project idea examines whether adding gelatin causes a solid to have a higher melting point and/or melt slower.

Construct and experiment with a periscope using reflected light rays to gather an image.

This science fair project idea explores whether the process used to dry the beans we eat for food renders them unviable.

What's the chemistry behind dyeing Easter eggs? Will adding vinegar to dye help the eggshell absorb the color? This colorful science project has the answers!