Experiments with magnets appeal to children of many ages. Invisible magnetic forces amaze children by "magically" moving metal objects before their eyes. Demonstrate attraction, repulsion, and polarity by using common classroom supplies and introduce the corresponding science terms with each activity. Allow children plenty of time to conduct their own investigations with magnets.
Devise a simple test to measure the strength of a magnet. The KidsGen website suggests using a rubber band to attach two metal washers to the end of a ruler. Attach a magnet to the opposite end of the ruler. Tape a cardboard tube to the table, then lay the ruler across it like a see-saw, positioning the end with the magnet up in the air. Hold a second magnet directly over the first, slowly moving it down until the ruler tips over. Without moving the second magnet, use another ruler to measure its height above the table. Repeat the experiment with different magnets to compare their strengths. Magnets that must be held very close to the first magnet in order to tip the ruler are weaker than those that can tip the ruler from father away.
According to the "Exploratorium" website, magnets can create movement in chaotic ways yet simultaneously follow an orderly pattern. Explore this apparent contradiction by creating a magnetic pendulum. Place four circular magnets on top of each other in a stack to align their poles. Mark each magnet to indicate its north pole. Attach a ring stand to a clamp, then tie one of the magnets to the end of the ring stand so that it hangs freely. Place the other magnets on the base of the ring stand in a triangle shape, making sure the north poles are on top. Raise the clamp so that the hanging magnet cannot touch the other magnets or the base. Push the hanging magnet and observe the interactions of the various magnetic fields. Move one of the magnets to a slightly different position on the ring stand base to create a new pattern of movement.
The "Kids Science Experiments" website describes a demonstration involving toy cars. Place bar magnets on top of two toy cars and secure them in place with a rubber band. Position the cars so that the magnets face each other, leaving a small space in the middle. If the like poles of the magnets point toward each other, the magnetic repulsion will push the cars apart. If the opposite poles of the magnets face each other, the magnetic attraction will pull the cars together.
Design a magnetic maze, as suggested by the "Kids Science Experiments" website. Draw a maze on a thin piece of cardboard. Place a paper clip, metal washer, or safety pin on top of the maze. Hold a magnet under the cardboard and use it to move the metal object through the maze. Alternatively, pour a small amount of iron filings onto the cardboard and move the magnet to guide them through the maze.