Download Magnetism - MWMS HW Wiki

Magnetism
History of Magnetism

Magnetism was discovered in Magnesia
Greece (which is now Turkey)
 A mineral in rocks that is magnetic was
discovered. This mineral was called
magnetite. The name of these rocks are
called lodestones.
Three Properties of Magnets
Allowed to swing freely, one part of a
magnet will always point North.
 Magnets contain iron and materials that
contain iron.
 Magnets attract and repel other
magnets.

Magnetic Poles
All magnets have a North and South
Pole. A magnet is the strongest at the
poles.
 Like poles repel each other.
 Opposite poles attract each other.

Magnetic Fields
The region around a magnet in which magnetic forces act.
Magnetic Earth
Earth is compared to a bar magnet because it has
a magnetic field and poles
Structure of the Atom
Spinning electrons
produce a magnetic
field. This makes the
electrons behave like
tiny magnets.
Magnetic Domains
Magnetic domains are groups of atoms
that have their magnetic fields aligned.
 Magnetized materials have their
domains arranged in the same direction.

Ferromagnetic Materials
Ferro comes from ferrum which means
iron in Latin.
 Ferromagnetic materials show strong
magnetic properties.
 Examples: iron, nickel, cobalt,
gadolinium, samarium, neodymium

Making, Changing, and Destroying
Magnets
Permanent magnets are made from
materials that keep their magnetism.
 Temporary magnets are made from
materials the easily lose their
magnetism.
 Heating a magnet, stroking a magnet
back and forth with another magnet,
and striking/dropping a magnet can
destroy its magnetism.

Breaking Magnets

If a magnet is broken in two, you end up
with two magnets each with a North and
South pole.