Can Magnets Attract H2O Molecules?

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In summary, water is not truly magnetic, but it is paramagnetic due to the unpaired electrons in oxygen's p_x* and p_y* orbitals. However, this magnetic moment is very weak and impermanent. In contrast, solids with unpaired electrons in d-orbitals can have large permanent magnetic moments and exhibit ferromagnetism.
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mapa
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I understand that H2O is polarized. The way I see it there is a north pole and a sole pole. If this is correct, why does it not attract magnets?
 
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Thanks for the help.
 
  • #4
H2O is really not truly magnetic. When you say "magnetic" you probably mean "ferromagnetic" or that it has a permanent magnetic moment. Water can't, because there's no "spot" where unpaired electrons could permanently "live".

Water is paramagnetic, which means that it has a slight magnetic moment, because the last two electrons in oxygen's shell are unpaired and each one is in the p_x* and p_y* orbitals. You can measure this in something called a "gouy balance" - same thing w/ O2 gas or O2 liquid. There's a ton of switching around of these electrons (note the "*", meaning they are in special "antibonding" orbitals), so that's why you only get a very mild, impermanent magnetic moment.

Water has a "big" electric dipole moment, however, b/z oxygen is so electronegative, that the bulk of the time the electrons that came along with, and are covalently shared by, the two hydrogens, spend their time around oxygen.

In solids, where lots of unpaired electrons can permanently live in the crystalline unit cells of compounds like cobalt-iron-neodymium or what have you, can and do have very large permanent magnetic moments...all the unpaired electrons EACH occupy a d-orbital...since they're all pointing in one direction (due to Hund's rules and the Aufbau principle), there's your permanent magnetic moment and, hence, ferromagnetism. Does that help?
 
  • #5
solidspin said:
Water is paramagnetic, which means that it has a slight magnetic moment, because the last two electrons in oxygen's shell are unpaired and each one is in the p_x* and p_y* orbitals.

I'm afraid you've confused water with O2 and atomic orbitals with molecular ones.
Water has no unpaired electrons and is thus diamagnetic. Which, (for the benefit of the original poster), means it's even less magnetic than that - about as un-magnetic as a substance can get.

It's O2 that has two unpaired electrons (in the [tex]\pi^*_x[/tex] and [tex]\pi^*_y[/tex] molecular orbitals), and is thus paramagnetic.
 

1. Can magnets attract water molecules?

Yes, magnets can attract water molecules because water is a polar molecule. This means that it has a positive side and a negative side, and the opposite poles of a magnet will attract each other.

2. How do magnets attract H2O molecules?

Magnets attract H2O molecules through the force of magnetism. This force is created by the movement of electrons in the magnet, which creates a magnetic field that can interact with the polar nature of the water molecule.

3. Can magnets make water molecules move?

Yes, magnets can make water molecules move. This is because the magnetic field created by the magnet can interact with the polar nature of the water molecule, causing it to align and move in a certain direction.

4. Do all magnets attract H2O molecules?

No, not all magnets can attract H2O molecules. Only magnets with a strong enough magnetic field can attract water molecules. The strength of the magnetic field depends on the material of the magnet and its size.

5. What happens when water molecules are attracted to a magnet?

When water molecules are attracted to a magnet, they will align themselves with the magnetic field and move towards the magnet. This can be seen in small droplets of water forming around the magnet or when a magnet is placed near a stream of water.

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