Question
Indicate which is lower in energy in a many-electron atom:
3d or 4s
Would it be 4s [because it fills before 3d]?
That is correct is almost all cases. There is an exception for Cr and Cu; however, I think the intent of the problem clearly means the 4s (and for the reason you sited).
3d or 4s
Would it be 4s [because it fills before 3d]?
That is correct is almost all cases. There is an exception for Cr and Cu; however, I think the intent of the problem clearly means the 4s (and for the reason you sited).