Small particles like electrons, quarks, and protons have properties like mass, charge, and the intrinsic "magnetic moment." The magnetic moment describes how much like a "magnet" these particle will behave. Electrons have a magnetic moment about 1000 times large than the proton. Because of this huge difference, we will ignore the magnetic moment of protons.

Electrons exist in atoms in orbital shell. When a shell is filled by a pair of electrons, their magnetic moments cancel each other out.

But if some of those shells are filled with single electrons, then the atoms will behave more like magnet.

The most magnetic naturally occurring substances are iron, nickel and cobalt. Neodymium, (element number 60, Nd,) is used as an alloy of Neodymium-Nickel-Cobalt to make the strongest magnetic material. Typically these magnets are referred to simply as, "Neodymiums."

Materials that are very magnetic are said to be Ferromagnetic. This term comes the periodic symbol for iron.

When electrons get together in a substance some of their magnetic moments group together such that most will point in the same direction. This region of the same direction is called a domain. Domains vary in a substance like iron. The more domains you get to line up the stronger the magnetic property.

Here is a substance with various domains, These domains point in random directions. But some point in the same direction. (They are yellow.)

You would probably not consider the materials above very "magnetic." The material below has so many domains lining (in yellow,) up without any outside magnetic fields to push them around that it would be considered ferromagnetic.

In other words it is what you would call a permanent magnet.

Below is a piece of iron that is place in an external magnetic field. When hit, domains are given the energy to move in place. These domains line up with the external magnetic field. This increases the materials magnetic property.

If you break a magnet you get two smaller magnets. Each with a north and south pole.

You can keep doing this until you get down to electrons and protons. Each time you will get a smaller magnet with a north and south pole. If you could break the electrons you get a Nobel prize or a very big electric bill. ...But you would no get a smaller magnet ;-)

Monopoles are described as the existence of either a north pole or a south pole. Stable monopoles do not exist. If any one tries to sell you a monopole magnet, don't buy it because it is not real.

Like electric fields, magnetic fields provide an invisible structure in space for delivering a force.

Like other fields, magnetic field lines, (referred to as b-field lines,)

• do not touch each other and
• are perpendicular to the surface.

Here are some characteristics specific to b-fields

• B-fields exist inside of the magnetic material. (Electric fields can exist inside of insulating containers but not containers made from a conductor.) This is because magnetic fields are created by the electrons inside of the materials.
• B-fields seek the south outside of the magnetic material.

Below is a magnetic field for a bar magnet.

• The b-field lines point in the same direction, the source of the fields are repelled.
• The b-field lines point in the opposite direction, the source of the fields are attracted.

In the image below the b-field lines point in the same direction. Therefore the two magnets are repelled from each other.

Answer the four questions below based on the picture below.

True or False