# Nuclear shell model spin and parity?

1. Jan 31, 2012

### humanist rho

1. The problem statement, all variables and given/known data
What is the shell model spin and parity of $$_{38}^{89}Sr$$?

2. The attempt at a solution

If i fill the levels as we usually do,

Protons will end up in the level $$1f_{5/2}$$ with 6protons,ie the level is completely filled

If the neutron number is considered,$$1g_{7/2}$$ with 1neutron is the final level.

Then what is the spin parity?
$\frac{5}{2}^{+}$ or $\frac{7}{2}^{+}$?

2. Feb 2, 2012

### humanist rho

In a book i saw tha spin parity of oxygen is found by considering proton number only.I want to confirm if it is so even when the proton shell is completely filled(ie, there's no unpaired proton).or do i need to consider neutron number?

3. Feb 18, 2012

### GothFraex

You have to consider any unpaired nucleon (protons or neutrons).
In this case the protons are all paired up and you have 1 unpaired neutron.
The unpaired nucleons determine these properties of the nucleus.