Question: What makes magnets magnetic?

Simone answered on 6 Nov 2018:

The magnetic properties (or the total magnetic field) of a material is mostly due to electrons spinning around themselves and around their nuclei in the atoms of the material.

The electrons spinning around their own axe have 2 way to do so (like a basketball that is spinning around itself and can do it either from left to right or right to left). These two ways for the electrons to spin are called spin-up and spin-down.
An electron spinning around itself is basically a charge moving (a current), and through the laws of electromagnetism we know that it leads to the generation of a magnetic field.
However, the magnetic field associated to the spin-up is opposite the the one associated with the spin-down and the two magnetic fields normally cancel each other out.

In atoms, each orbit around the nucleus can accommodate maximum 2 electrons and they always have to spin in opposite ways (1 spin-up and 1 spin-down).
If the atoms of a material do not have enough electrons to fill all the orbits they will have some of them with just 1 electron in it.
This atoms are said to have unpaired electron spin and so the magnetic field associated with the spin of that lonely electron is not cancelled out by another electron spinning in the opposite way.
This results in atoms with a net magnetic field.

Now, if all these atoms in the materials are facing the same direction, their magnetic fields will be aligned and will add up, resulting in a magnet like the one that attracts iron. This material is called ferromagnetic.

If these atoms are not facing the same direction, then all of their atomic magnetic field will be averaged out in the material and we cannot see magnetic properties directly.
However, if we apply an external magnetic field to this material, these atoms will tend to align to it, producing a net total magnetic field, and the material will become magnetic.
This type of material is called paramagnetic.

Materials made by atoms with all the orbits full won’t have any magnetic properties instead.