Which of the following is a correct electron configuration?

Question

A 1s2 2s2 2p5 3s2 3p6 4s2 3d10 4p3
B 1s2 2s2 2p6 3s2 3p6 4s2 4p3
C 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3
D 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p3

C?

Answer 1

I would go with D. That places the D level before the s and p levels and that's the way the configurations are drawn.