This science fair project idea determines whether eating before or after exercise is more beneficial to health and performance.

Observe which kind of fresh long-stemmed flower will last the longest after being picked.

Is exercise a cellular activity? Check out this fun science fair project idea to compare the carbon dioxide production before and after exercise.

This science fair project idea explores whether boiling and freezing water will have an effect on how much it weighs.

This science fair project evaluates if and how eating a large meal affects ability to perform mental tasks.

This project explores how and how much one family can reduce the amount of garbage they accumulate over a three month period.

This project is about after-images and what possibly affects them.

Compare different remedies for cooling the mouth after eating spicy food.

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.

This experiment examines if space objects become round after reaching a certain mass.

This project determines how much the rebound rates of tennis balls change after ten games.

In this experiment, students find out what happens when a less-dense fluid interacts with a denser one, replicating the effect of cooler solid rock on magma.

Determine whether a hot liquid cools off faster when liquid is added before or after a two minute wait.

Assess physical and mental states of subject before and after drinking coffee. Compare initial expectations with their reported conditions.

What can you do with hair after its cut? This science project teaches you practical uses for human hair.

Discover whether the â5-second ruleâ is effective at determining whether food is still safe to eat after being dropped on the ground.

Research fruits and their ripening stages, follow and document the different stages. Analyze what causes fruit to continue ripening after being picked.

This experiment will evaluate bacterial content on toothbrushes before and after different cleaning methods to determine which method of disinfecting is best.

Research active ingredients in anti-aging creams. Test skin creams on volunteers, document the effectiveness of the creams with before an after photographs.

Study the effect of music on blood pressure. Compare blood pressure readings before and after the listening session. Analyze results, write a detailed report.

Compare the whitening abilities of four different brands of whitening toothpaste to see which one whitens the fastest and which one whitens the most.

You've heard all about oil spills, but can they really be that bad? After all, vegetable oil is in almost every yummy baking good from cookies to brownies.

This experiment explores how listening in to a one-sided conversation affects concentration.

Test out various brands of permanent markers to see which one is least water soluble.

This project compares the strength of one, two, and three-ply toilet paper.

What happens when "coffee-addicts" miss coffee for 1 day? Find out in this science fair project idea!