1. The problem statement, all variables and given/known data Write all possible terms (n1 j1, n2 j2, …) J for these electronic configurations (considering jj coupling scheme): 1s2 1s2s 1s22s22p 1s22s22p5 3. The attempt at a solution 1s2 I have two electrons in the s sub-shell, since |l-s|<=j<=l+s then j1=1/2 and j2=1/2. This gives possible J values of J=0,1 and the terms are (1/2,1/2)0 (1/2,1/2)1 1s2s one electron in 1s and one in 2s. Again using a rule |l-s|<=j<=l+s gives j1=j2=1/2 for both electrons. j1 and j2 can couple together go give total J=0,1 so the terms are again (1/2,1/2)0 (1/2,1/2)1 So far I'm not sure that this is right, do I have to do this calculations with all electrons or can I ignore completely filled shells ? But what about 1s2s then ? Also is my designation of these terms like (j1,j2)J correct ?