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

In this popcorn experiment, students can explore how two things made out of the same material can have very different appearances and densities.

In this experiment, your child will create two compost bins and see if he can determine what attracts fruit flies.

Milk is made of water and fat; but how can you separate the two? Find out in this color changing milk experiment.

This classic children's game-connecting two cups with a string-demonstrates sound's ability to travel through air vs through a solid.

What do ants eat? Kids find out by observing a colony of ants in this cool zoology science fair project for 4th grade.

Free science fair project idea that examines the differences between cats and dogs. Analyze objective qualities rather than subjective ones.

Help your second grader observe the phases of the moon, and then let the fun loose: he'll get to chart his observations with marshmallows!

In this project, learn about animal vision and different kinds of eyes: ocelli, compound eyes, and camera eyes. Find out what a jellyfish or grasshopper sees!

What animals are most popular? This project affords practice in data-collection, record-keeping and data-analysis through the investigation of this question.

This project demonstrates the correspondence between the volume of water displaced by a submerged object and the volume of the object displacing it.

Test whether plants can grow without sunlight and water.

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

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.

This project explores whether plants can live and grow when "watered" with juice, soda, or milk.

In this project children practice the scientific method while playing with puffy paint.

The objective of this science fair project is to observe the differences in heat absorption for darker colors vs. lighter colors.

In this science fair projects, students will grow out the bacteria that collect on air conditioner filters.

In this experiment you explore how tectonic plates move to create land and expand bodies of water.

This science fair project idea explores whether the process used to dry the beans we eat for food renders them unviable.

This science fair project idea investigates if webbed feet help a duck (and others) swim.

This science fair project idea investigates which objects float and sink in honey, water, and oil.

This science fair project idea explores how length affects the weight a bridge can hold.

This science fair project idea investigates how a bottom keel helps keep a boat from rocking back and forth.

Here's a great activity that uses corks and toothpicks to create a fleet of floating boats. Which design makes for the most seaworthy vessel?

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