# Conservation of angular momentum in nuclear physics

1. Mar 18, 2014

### burgjeff

Say a uranium-238 nucleus with angular momentum II decays to thorium-234 plus an alpha particle. Will the sum of the angular momenta of the thorium-234 nucleus and the alpha particle equal II? What if a photon was emitted during this process, would Ithorium+Iα+hbar=II?

thanks

2. Mar 18, 2014

### Staff: Mentor

The relative motion of the nuclei can carry angular momentum, so the result can be different.

3. Mar 19, 2014

### dauto

To clarify mfb's point, orbital angular momentum must be included when applying angular momentum conservation. But yes, angular momentum is definitely always conserved.