1. The problem statement, all variables and given/known data Consider the electronic configurations [Ar]3d94s1 and [Ar]3d10 for an atom. (a) Identify this element. (b) Use Hund’s rules to explain which is the ground state. Show your work for full credit. 2. Relevant equations J=L+S n2S+1LJ L= l1+l2 S= s1 + s2 or S = (1\2)* number of electrons J = range from |L-S| to |L+S| 3. The attempt at a solution I'm pretty sure that the element in question is Ni, because it doesn't say anything about being an ion. But I'm having some trouble understanding how to apply Hund's rules. So I'm trying to use the LS coupling scheme to get the total angular momentum J to make an energy level diagram but I'm not sure I've done it right because every example I've seen has used two electrons in the same shell (so same value n). So what do you do when you have two electrons in two different shells (different n's)? First I looked at only the unpaired electrons and used the above equations to get: 3d9--> n=3, l=2, ml=-2,-1,0,1,2 4s1--> n=4, l=0, ml=0 L = 2 S = 1 J = 1, 2, 3But then, when I go to put it all together, I come to the two different principle quantum numbers problem. So how would I use the n2S+1LJ notation in this case? Would there be two different notations for each n? And the ground state should be something along the lines of n3D1 right? Then for the 3d10 configuration, how would you apply Hund's rule if all the shells are full? I know that unfilled shells have lower energy, so I'm fairly certain that the 3d94s1 configuration would be the ground state, but how could I quantitatively describe the 3d10 state? Or am I just doing this all wrong?