1. The problem statement, all variables and given/known data 1)Give in spectral notation the possible states of an atom which has a closed core plus one d electron. 2. Relevant equations 3. The attempt at a solution I solved in the following way: For d electron, Orbital angular momentum quantum number(L)=2 Spin angular momentum quantum number(S)=1/2 Possible values of total angular momentum quantum number(J)= L+S,| L+S-1|,…,|L+S| Hence, J= (2+1/2), |2+1/2-1|,|2-1/2| J= 5/2,3/2,1/2 Possible states of the atom in spectral notation are, 2 D 5/2, 2 D 3/2, 2 D ½ But the answer given in my book is 2 D 5/2, 2 D 3/2.