In this science and engineering activity, children will explore types of tunnels and their purposes and then design and build a tunnel of their own.

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.

Use a dichotomous key to identify plants or animals.

Think about the adaptive utility of an important aspect of our physiology.

How does a compass work? What's a magnetic field? Kids will build their own compass at home to find the answers in this great science fair project idea.

Is it possible to trick the forces of nature that make your bubbles round to create a square bubble?

Give your child a chance to experiment with how things grow. And throw in something extra to up the fun factor even more...her very own grass pet!

What are the effects of fertilizer on plant growth? What's the best fertilizer type (solid, liquid or powder)? Kids find out in this science fair project idea.

Science fair project that compares the ecology of different soil samples by identifying which sample has the most invertebrates living in it.

This science fair experiment examines the relationship between gender, age, and smiling.

This science fair project idea focuses on saturated and unsaturated lipids (fats and oils).

Learn how different types of soil affect how animal tracks form in this experiment!

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

Learn about savanna flora and fauna in this science project! Take a look at characteristics of tropical grassland plants and animals that help them survive.

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.

This science fair project looks one of the most important factors affecting seed germination: water. A fun and easy plant biology experiment for 3rd graders.

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.

Determine how good we are at direct and indirect observation.

Science fair project which determines whether it is numerically possible to be connected to every person on the earth within six degrees of separation.

Why do ants like sugar? Do ants like artificial sweeteners too? Kids find out with this great inquiry-based science fair project.

What are buttress roots? In this fun science project, make a model of a rainforest tree and learn how they help trees survive in the tropical rainforest!

In this enlightening transpiration experiment, kids will explore how the loss of water from plants through transpiration contributes to the water cycle.

This science fair project will help learners determine whether algae can be made to grow by feeding it supplementary carbon dioxide.

This 4th of July, explore fourth grade science and make some safe fireworks in your own backyard using soda pop!

In this cool science fair project idea, kids conduct the ruler drop test on volunteers to determine whether reaction time can be improved with practice.

In this simple circular motion experiment, you'll observe tangential velocity and learn about how acceleration and centripetal force affect an object.

Check out this fun leaf chromatography science fair project idea for middle school students and discover the hidden pigments in leaves.

In this activity, your child will be asked to create a boat that can successfully float while holding 25 pennies.

This science fair project idea determines if the color of light affects the growth of plants.

Science fair project that examines how light wavelengths affect photosynthesis in the aquatic plant: Elodea.