Magnetism & Electromagnetism The Nature of Magnetism Chapter 1 Section 1

Magnets Magnetism The attraction of a magnet to another object

Magnesia (in Greece) Used over 2,000 years ago Magnetite Mineral found in some rocks Fe3O4 Attracts iron

Lodestones Magnets swinging on strings will eventually point toward the … Lodestar Means Leading Star Aka North Star Discovered 1,000 years ago

Magnetic Poles The area of the magnetic where the magnetic effect is strongest North Pole South Pole

Interactions Between Poles Like poles repel, Unlike poles attract

Breaking a Magnet Produces smaller magnets

Magnetic Fields The magnetic force exerted all around a magnet Magnetic Field Lines Spread out from one pole, curve around the magnet and return to the other pole Never cross

Elements One of about 100 basic material that make up all matter Atom The smallest particle of an element

In an Atom Bigger, in Nucleus Electrons Protons Neutrons Small “+” charge Neutrons No charge Electrons Small “-” charge Orbits nucleus Produce a small “Atomic Magnetic Force”

Magnetic Domain A cluster of billions of atoms that have magnetic fields that are lined up in the same way Magnetized Material All/most of the domains are arranged in the same direction

Ferromagnetic Material A material that shows strong magnetic effects Iron, Fe Nickel, Ni Cobalt, Co

Making Magnets Some materials can be magnetized if rubbed with a strong magnet Typically just temporary Magnetic Domains become aligned

Destroying Magnets Knocking the domains out of alignment Drop it Strike it Heat it

MagLev 400 km/hr Floats a few cm’s above tracks 250 mph No vibrations No noise from the steel tracks