This science fair project explains the process of how the lungs expand and contract with the help of the diaphragm.

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

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

Learn the basic structure of a DNA strand, which is the double helix, how genes form together, and the resemblance DNA has to a twisted ladder. Create a model.

Learn how to make a hygrometer to measure relative humidity in this project. Make a sling psychrometer hygrometer with gauze, thermometers, and a bottle.

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.

Explore how sound waves are reflected and absorbed by producing echoes. Analyze which locations produce echoes.

How do series and parallel circuits work, and which produces the brightest light in a light bulb? Construct both in this project and find out!

Kids get step-by-step instructions for how to make a rubber band car and explore the physics of potential energy with this fun engineering science fair project.

Explore if planting seeds in a certain direction will affect how fast it germinates.

It's not actually that hard to get energy from garbage! Kids learn how to make biogas in the form of methane with this cool and easy science fair project idea.

Demonstrate how to tell the age of an egg without having to crack it open.

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

How greasy are your potato chips? Students will use a reliable method to quantify greasiness and compare different brands in this great science fair project.

Kids will learn how to make a steam powered rocket boat, also called a putt putt boat or a pop pop boat, in this great science fair project for 4th graders.

Check out this fun science fair project to make a vinegar and baking soda balloon and demonstrate how gas is created as a result of the chemical reaction.

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

You've heard the expression "burn rubber" but do you know how heat affects rubber? Examine the impact of temperature on rubber in this fun science experiment.

The objective of this science fair project is to experiment with balancing everyday objects and observing the the effects of gravity on materials.

In this experiment we will be determining whether birds prefer certain colors of seed.

Soil is made up of different layers. How far down do you need to dig to find the soil horizon, or the place where bits of leaves and branches become soil?

In this windmill model science project, you will build a windmill to learn about wheel-and-axle machines and how these simple machines are used to do work.

The objective of this science fair project is to analyze the effects of salinity and temperature on water.

This science fair project idea discovers whether there are some objects that do not fall at a constant rate.

This science fair project idea discovers if an artificial light source will yield the same plant health and growth rates as light from the sun.

This project examines if computer screen and text color affect retention and if people subconsciously prefer combinations of colors that help their retention.

This science project teaches students about organic farming and the benefits and disadvantages of commercial plant food.

This science fair project investigates whether tapping the top or the side of the can will stop a vigorously-shaken can of soda from exploding.

This science fair project creates a visual model of whatâs happening to sound waves as a car approaches and then leaves.

Science fair project examining barometric pressure, and how it can be used to predict the weather. How does atmospheric pressures relate to weather conditions?