The Naked Scientists

The Naked Scientists Forum

Author Topic: Why don't magnetism and static electricity interact?  (Read 4087 times)

Offline ScientificSorcerer

  • Sr. Member
  • ****
  • Posts: 367
  • Thanked: 2 times
    • View Profile
It is a well known fact that static electricity and magnetism don't really interact with each other. But my question is why? I know that on a sub atomic level, magnetism is only able to occur in elements with a half shell of valence electrons or near a half shell.

SO if you positively charge a magnet with static electricity wouldn't you be stripping away some of the valence electrons from the magnet and cause it to no longer have a half shell of electrons thus causing the magnet to temporarily loose it's magnetism? why doesn't this happen, you would expect at least something to happen right?

Also as a side note, is it true that when you magnetize something it causes the spin of all valence electrons in a sample to align?
« Last Edit: 04/06/2014 10:45:42 by Georgia »


 

Offline evan_au

  • Neilep Level Member
  • ******
  • Posts: 4120
  • Thanked: 245 times
    • View Profile
Re: Magnets vs static
« Reply #1 on: 02/06/2014 11:20:03 »
Quote
static electricity and magnetism don't really interact with each other.
I would rather say that "static electricity and static magnetism don't really interact with each other".

But if a static charge is moving relative to a magnet, then they do interact with each other.

Quote
magnetism is only able to occur in elements with a half shell of valence electrons or near a half shell
The Pauli exclusion principle ensures that if a shell of electrons is (almost) full, then (almost) half of the electrons will oppose the magnetic effect of the other electrons, (almost) canceling it.

However, it does not need to be the outer (valence) electrons which are unpaired - it is possible for a magnetic field to originate in atoms which have unfilled inner shells. These may be shielded from static effects of the outer electrons.

When you do charge up a magnet, you will be subtracting (or adding) electrons from a very small fraction of atoms in the magnet - and mostly affecting the atoms on the outer skin of the magnet. This will have little effect on the bulk of magnetic atoms, which are in the interior of the magnet.

Quote
Is it true that when you magnetize something it causes the spin of all valence electrons in a sample to align?
Having all the unpaired electrons aligned is a fairly high-energy state. You can reduce the total energy by turning it into two (or more) regions with opposing magnetic fields.

These zones of different magnetic fields are called magnetic domains, and they can expand or shrink depending on external magnetic fields. What makes Ferromagnets so strong is that these magnetic fields tend to line up in the same direction over microscopic distances, while in most materials, they only line up over atomic scales or the nanoscale.

If you randomise the magnetic fields of these domains (eg by heating the material beyond its Curie temperature, and then cooling it again), it will become demagnetised - or take on the relatively weak magnetic field of the Earth.
 

The Naked Scientists Forum

Re: Magnets vs static
« Reply #1 on: 02/06/2014 11:20:03 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums
 
Login
Login with username, password and session length