8.1 Magnetic Materials
Magnetism is a force that acts at a distance upon magnetic materials. These materials are attracted to magnets. Materials such as iron, nickel, and cobalt are attracted by a magnet. They are called magnetic materials. Materials such as brass, copper, gold, glass, and plastic are not attracted by a magnet. They are called non-magnetic materials.
lightbulbFor Your Information! Over 1000 years ago, the Greeks discovered a rock called lodestone or magnetite that could attract materials that contained iron. Also, if suspended from a string to rotate freely, it would always settle in a north-south direction. This unique property led to the formation of the compass, which was later used for navigation on land and at sea.
If iron filings are sprinkled on a thin glass plate placed over a magnet and the surface is gently tapped, the filings form a pattern. This activity also shows that magnets can attract objects containing iron even if they are not in direct contact with them.