# Homework Help: Does the hydrogen atom have a spin?

1. Aug 14, 2008

### learning_phys

does the hydrogen atom have a spin?

since it has a proton (spin 1/2) and an electron (spin 1/2) then does they hydrogen atom have spin 1?

2. Aug 14, 2008

### OmegaMax

Re: hydrogen

I'm afraid it doesn't work like that. While hydrogen is indeed made of a proton and an electron it does not have a spin. The reason for this is that spin is an intrinsic property of sub atomic particles. So even though the proton and electron come together, sort of, to form an atom their intrinsic properties remain there own. On that note; remember that spin has direction associated with it i.e. if the proton were spin up + the electron spin down, then the hydrogen would have no or zero spin. See the discontinuity. If hydrogen had spin it could only have one magnitude.If you want to learn more check out the web for or wikipedia "The Standard Model".

3. Aug 14, 2008

### learning_phys

Re: hydrogen

so protons have spin 1/2, however it is no fundamental like the electron. it has quarks. do quarks contain the intrinsic properties of spin (which projects/adds up to give the proton of spin 1/2)?

also what about deuteron? it has spin 1 but it's the addition of the proton and neutron spins?

4. Aug 15, 2008

### OmegaMax

Re: hydrogen

Yes, everything changes when you start adding quarks, which do have spin. What essentially makes a proton different from a neutron is the charge and the spin, or more precisely the quarks that make up each. Since Quarks are the fundamental components of both protons and neutrons their spins can be added. The quarks involved in both are the flavors up and down. Up quarks have a spin of 1/2 up and a fractional charge of +2/3, while down quarks have a spin 1/2 down and a fractional charge of -1/3. A proton is formed from three quarks two up and one down, similarly a neutron is formed of two down and one up. A deuteron or for that matter any nucleon can have spin because you are just adding quarks. Also, quarks are held together by the strong force which has associated with gluon particles. If you want to learn more look up Quantum Chromodynamics or wikipedia quarks.

http://en.wikipedia.org/wiki/Image:Quark_structure_proton.svg

Last edited by a moderator: Apr 23, 2017