What Compounds Are Effected by Magnets?

Ferromagnetic Materials

• Some compounds are attracted to magnetic fields and are called "paramagnetic." The elements that are the most strongly attracted to magnetic fields are cobalt, nickel and iron, which are called ferromagnetic substances. These elements combine with other elements to form a broad range of compounds. Coins and silverware often contain materials that make them ferromagnetic, so they are attracted to magnets. With most elements, pairs of electrons pull atoms together. Ferromagnetic materials have extra electrons that pull other objects to them.

Electromagnets

• A Danish scientist, Hans Christian Oersted, discovered that magnetism was the result of a force between two different electric currents. Parallel currents in the same direction attract, while opposite direction currents repel. Flowing electricity through metal can create an electromagnet. Electromagnets line up the nuclei of hydrogen atoms. This factor influences why physicians can use nuclear magnetic resonance to scan hydrogen-containing compounds in the human body.

Steel

• People can magnetize steel by rubbing it on a magnet, since electrons line up as a result. Then, other metals will be attracted to the steel. Steel is a metal that has both iron and various other alloys. The iron gives steel its magnetic properties.

Copper, Aluminum and Plastic

• Some compounds are repelled by the magnetic field and are called "dimagnetic." Copper, aluminum and plastic are the least influenced by magnetic fields. Compounds can become very non-magnetic when they have anti-ferromagnetic properties and are exposed to very low temperatures. However, any materials that are alloyed with iron will become more magnetic.

Earth's Mantle

• The Earth as a whole has a magnetic field. No one knows for certain why this is the case, though scientists have come up with theories. Scientists think the motion of fluid and plasma in the Earth's mantle produce the magnetic field. The fluid motions rotate currents in the Earth, caused most likely by thermal convection and the Navier-Stokes equation.