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Q & A: magnetic particles: spin and charge

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Most recent answer: 06/08/2015
Q:
What particles are magnetic? May a magnetic particle have a zero spin number? May a magnetic particle have a zero electric charge? Give examples of nuclei which are magnetic. What nuclei are found in biomacromolecules? Which of them are magnetic? Which of them can be routinely studied by NMR?
- Itzel (age 20)
A:

"May a magnetic particle have a zero spin number? "

No. If a particle has a magnetic dipole moment, that points some direction. Since the universe doesn't have a favorite direction, it could be rotated to point other ways. That means that this particle changes as it's rotated. A spin zero particle by definition doesn't change as it's rotated. (We're assuming that the partcle's total angular momentum is called spin here.) The same basic argument applies to quadrupole moments etc.- they all change if rotated and thus can't be from particles with zero angular momentum.

"May a magnetic particle have a zero electric charge?" 

Yes, for example a neutron.

For applications of NMR to biology, you could look at .

Mike W.


(published on 06/08/2015)

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