# What do DC magnetic fields do to salt water.

1. Feb 17, 2010

### rogerharris

What effect does a DC magnetic field probe have when submerged in salt water ?

i.e. There is not an electrode..just a plastic insulator with calcium ions pulsing through it giving off a magnetic pulse submerged in salt water.

Sodium ions are paramagnetic, so would these be attracted to the probe ?
What about the chloride ions, these are diamagnetic..would the be repelled by the probe ?

2. Feb 17, 2010

### SpectraCat

Ummm ... what makes you think that sodium ions are paramagnetic? They have a closed shell .. basically a neon atom with an extra proton and neutron.

Anyway, any charged particle will feel a force from the magnetic field ... they will tend to bend around the magnetic field lines due to the Lorentz force: $$\vec{F}=q\left(\vec{E} + \vec{v}\times\vec{B}\right)$$. Since it is a pulsed field, that force will be time-dependent, and so any induced motions of the ions will be transient. I suppose if you got the field magnitude up and ran a pulse train through it, then this could be a bizarre way to heat up salt water. I think it would be pretty complicated to model though, given that it is happening in a fluid with both positive and negative ions present.\times

3. Feb 17, 2010

### rogerharris

my mistake ..it is the sodium molecule that wiki says is paramagnetic, not the ion.