Sink or swim? Calculate the density of various fruits and vegetables using water and a kitchen scale.

Science fair project which simulates the global conveyor belts on a small scale, and observes the effects of wind, density and temperature on water movement.

In this cool project, create a lighted, scale model of the different layers of the Sun, including the core, radiation and convection zones, and photosphere.

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!

This science fair project idea explores whether boiling and freezing water will have an effect on how much it weighs.

This project uses science and art to help students learn and teach others about Earth's endangered and extinct species.

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

This activity challenges your student to use spatial reasoning and computational thinking to program multiple robots.

Check out this cool science fair project on identifying rocks and minerals for kids.

This science fair project idea explores whether factors such as temperature and concentration affect the pH of a solution.

This experiment examines whether storing your orange juice at different temperatures affects its acidity.

In this experiment you will replicate the mummification process by making a hot dog mummy.

Total alkalinity and pH personal care products are controlled to prevent skin irritation. Learn more about basic and acidic substances in this science project.

This science fair project idea measures out the sugar of various foods and find out whether people can correctly determine how much sugar is in common foods.

This science fair project will help students learn about non-vascular plants, such as mosses.

The objective of this science fair project idea is to determine if sound travels best through the air, water or a solid.

This science project has students collect wood samples and invent new uses for different types of wood based on its properties.

This science project allows students to study the psychology of happiness.

The project investigates which soft drink is worse for your teeth by observing the affect of soft drink on limestone.

Teach your fifth grader about the wonders of wind by making and observing this winter wind chime.

Show your child how to construct a homemade thermometer. It's hands-on fun and a great way to learn about this important instrument!

In this open-ended activity, students will be given a small quantity of three types of materials and asked to design a prototype for “something that will improve the school.”

Do lefties just write different or are their brains different? This science project has students explore what it means to be left handed.

In this cool experiment, learn how to find specific gravity of minerals using liquids of different densities to see which substances and items sink and float.

Using an empty tennis ball can and a swimming pool, you will determine if it's possible to have a conversation under water.

This science fair project focuses on a polymer called hydrogel super absorbent crystal which absorbs water, swelling to many times its original size.

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

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

Demonstrate how you can make your own compass using a magnetized needle. It also allows you to compare magnetic north and geographic north.

Is horse manure a possible energy source in a crisis? Use calorimetry to find out how much energy horse manure can produce in this science fair project.