Question

Which of the following electron configurations is the most stable?

A. 1s^2 2s^2 2p^6 3s^2 3p^5

B. 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^5

C. 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2

D. 1s^2 2s^2 2p^6 3s^2 3p^6

E. 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10

Answer 1

Can anybody explain?

Answer 2

d orbitals are generally not stable. Option C has a full p orbital. Hence that is the answer.

Answer 3

They also add up to 18, which completes the octet configuration.

Answer 4

@RH

Answer 5

So C is the correct answer?

Answer 6

Yes. That is what I said.