Explain magnets at the subatomic level to me?

[kashiark]

Can someone explain magnets at the subatomic level to me? According to wikipedia, many of the electrons' spins are oriented in the same direction; what happened to the Pauli exclusion principle? Is it something to do with the electrons being delocalized that changes the other quantum numbers? Is a single atom of hydrogen magnetic?

 

[tiny-tim]

According to wikipedia, many of the electrons' spins are oriented in the same direction; what happened to the Pauli exclusion principle?

Hi kashiark!

The Pauli exclusion principle will only apply to electrons around the same nucleus …

they can't be in the same states …

but electrons round different nuclei are in different states anyway.

 

[Naty1]

Wiki notes at

http://en.wikipedia.org/wiki/Magnetism

In magnetic materials, the most important sources of magnetization are, more specifically, the electrons' orbital angular motion around the nucleus, and the electrons' intrinsic magnetic moment

Is a single atom of hydrogen magnetic?

If you read the above reference you'll find that "magnetic" vs "non magnetic" does not have a precise line of demarcation. My guess is that if you put almost any atom or particle in a strong enough magnetic field it will align itself at least in part with the magnetic field due to either electric charge, spin, or other factors.

Hydrogen would likely not make a good permanent magnet for use in a simple electric motor.

 

[kashiark]

What exactly is a magnetic moment? How does the spin of a single electron create a magnetic field when it spins?