Question

What causes magnetism, and what determines a magnet’s strength?

Answer 1

The material, the atomic and molecular structure of the material that is magnetized has a huge effect on the potential strength of a magnet. There are qualities of certain molecules that lend these molecules to being in a stable but electromagnetically polarized state.

Beyond that, the strength of a magnet depends on the degree to which the material is magnetized.

Even magnetic materials must have the magnetic fields of each molecule aligned, otherwise they will not exhibit magnetic qualities.

Usually magnetic materials are aligned in what is called domains; that is a group of molecules that acts as a sort of unit in the way they orient, sort of like the way that in a school of fish, all of the fish point the same way, but other schools may point in a completely different direction..If domains are randomly oriented, then there is no overall magnetic effect, but if they are aligned there is a clear magnetic effect, and the degree of their alignment is a measure of the total strength of the magnet; that is, the more domains are aligned to a certain direction, the stronger the magnet.