This science fair project idea recreates the movement of planetary bodies in order to learn why they sometimes appear to move backwards.

What are the benefits of good posture? Kids will learn about the cognitive effects of good posture through conducting and observing a controlled experiment.

What is condensation? Little mad scientists will learn about condensation, states of matter, and air pressure by conducting this cool science experiment.

Kids will learn how to show the direction of magnetic field lines and create a permanent model using iron filings in this great science fair project idea.

In this fun science project, learn about what happens to cut fruit and experiment with how to stop apples from turning brown.

Observe corn seed germination to learn about dicots and monocots and how plants grow from seeds to seedlings to full-grown plants!

How does water pressure change with depth? Kids learn how pressure works underwater with this cool and easy demo.

Do you have your isopods straight? Learn about sow bug and pill bug behavior by building a terrarium to study them in!

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

Can a toy car determine the strength of a magnet? In this cool magnet science fair project, young scientists will learn how to measure the strength of a magnet.

Kids will learn how to measure the viscosity of liquids by making their own homemade viscometer in this great science fair project idea.

Kids will learn some cool stuff about chemical reactions by determining what happens when you mix different concentrations of hydrogen peroxide and yeast.

In this experiment, you'll make a seafloor spreading model to learn more about how plate tectonics work and create mid-ocean ridges.

Kids learn about examples of mechanical weathering and conduct an experiment with seeds and plaster in this cool geology science fair project idea.

Climates with more snowfall have more coniferous forests and fewer deciduous ? Learn about how pine trees in a coniferous forest adapted to withstand snow.

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

Learn about the fruit fly life cycle in this experiment. Capture fruit flies to examine various stages of insect metamorphosis.

Learn about the role of Earth's rotation on the Coriolis Effect and hurricanes in this science project. Model the Coriolis Effect on a hurricane's direction.

4th graders construct an ocean food web to learn about consumers and trophic levels, food webs, and food chains in this cool ecology science fair project.

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

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!

Does the temperature of a magnet affect its strength? Learn about the relationship between magnets and temperature with this cool physics science fair project.

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.

What's the best way to make DIY compost? Kids will learn about aerobic and anaerobic decomposition while learning to appreciate the value of composting.

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.

What is biodiversity? Kids will study different areas of their backyards to see which is the most diverse to learn about biodiversity and random sampling.

In this simple science project, learn about what causes dew and what affects dew formation with a drinking glass, ice, and a soda bottle.

Learn about magnifying glasses, concave lenses and inverted images by sending rays of light through a magnifying glass in this cool science fair project!

In this cool physics experiment, use double plane mirrors at various angles to learn about light reflection. Then, see if you can solve a puzzling problem!