1. The problem statement, all variables and given/known data A beam of neutral hydrogen atoms in their ground state is moving into the plane of the page and passes through a region of a strong inhomogeneous magnetic field that is directed upward in the plane of the page. After the beam passes through this field, in how many beams was the original beam deflected? 2. Relevant equations 3. The attempt at a solution The electron and proton has both spin 1/2 so the total spin of the hydrogen atom, by the addition of spin and angular momentum can be 1 or 0, which means that the beam would not be deflected at all (spin 0) or would be deflected in 3 beams. However the answer seems to be that the beam will be deflected in 2 beams. Can someone explain to me why? Thank you!