Construct batteries that make electricity from fruits with this fun science fair project.

Wind is an important source of renewable, green energy. The purpose of this science fair project is to build and operate a windmill generator.

What chromosome combinations determine a fetus gender? Use probability to think about whether a sperm and ovum will create a male or female in this project.

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.

In this free science fair project, learn how to separate salt from water using heat. A great science project for elementary school kids.

For this science fair project, kids will learn how to make a lemon battery. They can conduct this classic experiment using readily available materials.

Tree rings can tell the age of the tree but also information about the world. This science experiment uses tree stumps to discover new facts.

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.

In this free science fair project, build a star clock and learn how to tell time on a clear night by observing the big dipper!

In this science fair project, learn how a mineral streak is made and how it can help identify an unknown mineral.

Dinosaurs were huge creatures that left behind huge footprints that lasted for millions of years. In this science fair project, kids learn how dinosaur tracks were left behind!

Does putting soapy water on plants help or hinder plant growth? Kids learn about greywater and how it affects plant growth in this cool science fair project.

This project examines whether playing music during class helps students learn or if it distracts students from learning.

How does distance affect the spreading of light? Kids see diffraction and the inverse square law of light in action with this great science fair project idea.

What heats up fasterâwater or soil? 5th grade students test the specific heat of water against the specific heat of sand in this great science fair project.

Children have a naturally inquisitive mind. Foster their curiosity with a walk through an autumn field or park to answer age-old “why” questions. As you walk with your child, you can encourage them to ask questions.

This science project teaches students the relationship between compost and plant growth. Students conduct an experiment with different types of compost.

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.

How does rust form? Kids will learn about the roles oxygen, water, and electrons play in rust chemistry in this cool science fair project idea.

In this science experiment, do tensile strength test on fishing line, a strand of hair, a rubber band, and any other materials you're curious about!

Science fair project that examines how to grow bacteria in a controlled setting, using simple materials from around the home.

Explore the craters, maria, and highlands on the surface of the Moon! In this fun science project you'll create a 3-D model of the moon using paper mache.

How does dishwashing liquid work? Kids discover the chemical mechanism behind cleansing power in this easy science fair project idea.

Ant behavior is closely related to light intensity. This free science fair project idea examines how fast ants dig when they are exposed to to light and dark.

What is a compound microscope? Kids find out by making one of their own in this cool science fair project.

In this cool engineering science fair project, kids learn how to build Hero's engine: an enlightening example of Newton's third law.

In this cool catalase and hydrogen peroxide experiment, kids put a potato in a jar of hydrogen peroxide to see how catalase acts as an enzyme.

Kids discover what a homogeneous mixture is by adding sugar to distilled water and identify the various factors affecting solubility.

Plants and light seem to be good buddies, but how far does the friendship really go?

Learn how to make a ping pong ball anemometerâa device used to measure wind speedâin this free science fair project idea.