Rather than telling students which items are and are not magnetic, provide a discovery activity and allow them to find out for themselves. Gather materials, some that magnets attract and some that magnets do not. Magnets best attract objects containing iron or cobalt. Choose some objects obviously not magnetic such as a chunk of wood and some that appear magnetic to students but are not, such as a dime. Provide students with several magnets and allow them to test the items you gathered to determine if magnets attract them or not. Have students sort and chart the items on paper as attracted to magnets or not.
Gather an assortment of magnets of various shapes and sizes. Have students explore the forces the magnets exert on each other. If this is a first exploration and students have no knowledge of the north and south poles of magnets, allow exploration and have students create a hypothesis about why the ends of the magnets sometimes attract and sometimes repel each other. Afterward, or if students have some prior knowledge of magnetic poles, review the facts concerning the way that a magnet's magnetic force extends out from the opposite poles of the magnet, generating a force field extending from the poles. After completing the exploration of the poles, have students create a diagram illustrating what happens when like poles rest beside each other and when opposite poles rest beside each other.
Provide students with a variety of strong magnets and a container of various objects. The objects should include pieces of fabric, small metal objects, iron filings, sheets of paper, a thin piece of wood, and a small container of rice or sand. Have students experiment to see which objects the magnetic attraction is strong enough to work through and which it is not. Instruct students to place the small metal objects on or in the various materials and attempt to move the object by placing the magnet under the material, paper, sand, wood or rice. Have students experiment to see which magnets work better through which materials. Students can also bury the small items in a container of sand or rice, hold the magnets over the container, and then see which objects the magnets attract and pull out of the sand or rice.
In 1832, Joseph Henry built an electromagnet that could lift 3,600 lbs. Have students explore electromagnets by creating a simple one from a battery, insulated wire and a nail. Have students wrap the insulated wire around a large nail, then connect the wire ends to opposite ends of a D-cell battery. The nail becomes magnetic and will pick up paper clips and other small objects. Have students experiment to compare the strength of the electromagnet with various other, nonmagnetic objects.