Let's suppose we can form 3He or ³H by adding a proton or a neutron to 2H, which has spin equal to 1 and even parity. Let be the orbital angular NUCLEAR PROPERTIES 79 momentum of the added nucleon relative to the 2H center of mass: What are the possible values of the total angular momentum of 3H or ³He? Given that the ground-state parity of ³H and He is even, which of these can be eliminated? What is the most likely value of the ground-state angular momentum of H or ³He? Can you make a similar argument based on removing a proton or a neutron from "He? (What is the ground-state spin-parity of He?) How would you account for the spin-parity of "Li and "He ()?