Is cleaning with lemon effective? Get ready to give this science project some elbow grease and find out if acidic lemons can be used as a cleaning agent.

What chromosome combinations determine a fetus gender? Use probability to think about whether a sperm and ovum will create a male or female in this project.

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

Science fair project which tests various sedimentary, igneous and metamorphic rocks to find out whether one rock family is stronger than the others.

The science project fair idea explores the interaction between your nose, mouth, and brain when tasting a new food or drink.

Test out the pH levels of soil in your backyard versus soil in more wild environments to solve this science case.

Check out this fun and easy 4th grade science fair project idea that tests how gravity induces positive and negative geotropism (gravitropism) in bean plants.

This science fair project demonstrates the magic of arches by challenging students to stack telephone books on top of eggs without breaking them.

The purpose of this science fair project is to demonstrate how yeast, a fungus, causes bread to rise.

The project is to investigate yeast fermentation and its results on hand of latex balloons.

This science fair project examines how seeds hitchhike on animals and clothing.

Observe how your brain works while it is focused on one thing, and how it works while you are distracted by another thing.

Science fair project that identifies the differences between soils from different environments and attempts to figure out why those differences exist.

In this pinto bean germination experiment, you'll learn about how fertilizer aids in growing pinto beans into seedlings.

Take a dive into the candy jar with this yummy science experiment.

How does distance affect the spreading of light? Kids see diffraction and the inverse square law of light in action with this great science fair project idea.

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.

This science experiment tests whether warm or cold water works best in making cut flowers last longer.

Science fair project which compares the rate of temperature change and the maximum temperature as a result of the angle of light radiation.

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

In this science fair project, students use the streak test to tell minerals apart from each other.

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

This science fair project uses paper chromatography to investigate whether black, brown, orange, and purple are pure colors or mixtures of other colors.

Science fair project which determines whether the size or the thickness of a piece of paper has an effect on how many times it can be folded in half.

Science fair project that determines whether cooling eggs helps them be peeled more easily. Compare the time it took to peel each egg.

Find out whether a longer airplane will fly farther or a wider paper airplane.

This science fair project idea explores how the shape of a boat affects its density and how much weight it can float.

How does rust form? Kids will learn about the roles oxygen, water, and electrons play in rust chemistry in this cool science fair project idea.

This science fair project idea identifies clouds as a means of predicting the weather.

Study the life cycle of the common blowfly as it relates to forensic investigation. Record the first time you see flies, maggots, and eggs.