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!

In this science experiment, observe convection currents forming and learn about how heat energy moves in liquids from hot to cooler areas through convection.

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.

In this project, build an insect model that shows how the head, thorax, and abdomen fit together! Learn insect anatomy by constructing a paper mache critter.

Learn about where colors come from and how light absorption works in this fun experiment! All you need is a flashlight, construction paper, and cellophane!

This is a fantastic and easy science experiment where kids will learn about elasticity by testing how high bouncy balls of different materials can bounce.

In this plastic wrap science fair project, you'll learn about polymer permeability and find out which plastic wrap keeps food from dehydrating best.

What are the effects of colored light on plant growth? Explore plant behavior in this cool botany science fair project and learn about phototropism!

Learn about the effect of artificial light on plant growth versus natural sunlight and delve into some biology and botany concepts in this science project.

Kids will learn how to make a thermometer to to explore liquid density in this great science fair project. Which liquids are affected by temperature the most?

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

Kids learn how to manipulate additive and subtractive colors to send secret messages with red colored filters in this cool science fair project idea.

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

In this experiment, kids will see if pruning tomato plants makes them more fruitful and learn about the factors that contribute to a plant's fruit production.

Kids will conduct a cool limewater carbon dioxide test that can be performed with common household materials to learn about the chemistry of this common gas.

In this cool science experiment, learn about magnetism and poles, and test magnet strength to find out if two magnets are twice as strong as one.

Kids construct a single fixed pulley system to learn how pulleys can make work easier in this cool physics and engineering science fair project idea.

How do animals keep warm? In this experiment, find out whether fat insulation resists cold temperatures and learn how this works in the animal kingdom.

Kids learn about potential energy, and mechanical energy, and how to make power from water with one of our favorite renewable energy projects for kids.