Question

Cobalt, Co, has 27 electrons. Write out the entire electron configuration for cobalt using spdf notation.

Answer 1

The complete electron configuration for cobalt (Co) with 27 electrons is 1s² 2s² 2p¶ 3s² 3p¶ 4s² 3d⁷, following the Aufbau principle, Hund's rule, and the Pauli exclusion principle.

Step-by-step explanation:

The electron configuration of cobalt (Co), which has 27 electrons, is written out in spdf notation as follows: 1s² 2s² 2p⁶3s² 3p⁶4s² 3d⁷. This notation shows that cobalt's electrons occupy the first four energy levels, filling the 1s, 2s, 2p, 3s, and 3p orbitals completely, and then adding two electrons to the 4s orbital before partially filling the 3d orbital with seven electrons. The order of filling is based on the increasing energy levels and follows the Aufbau principle, Hund's rule, and the Pauli exclusion principle.

Answer 2

Co = 1s2 2s2 2p6 3s2 3p6 4s2 3d7

Step-by-step explanation:

Number of electrons = 27

The closest noble gas before cobalt is Argon and argon has 18 electrons.

Co = [Ar] ; Remains 27 - 18 = 9 more electrons to fill.

The next orbital in order of increasing energy is the 4s orbital. However it can only hold a maximum of 2 electrons.

We have;

Co = [Ar] 4s2; Remains 27 - 20 = 7 more electrons to fill.

The next orbital in order of increasing energy is the 3d orbital. It can have a maximum of 10 electrons.

So we have;

Co = [Ar] 4s2 3d7

The electronic configuration of Ar = 1s2 2s2 2p6 3s2 3p6

This means the entire configuration of cobalt is;

Co = 1s2 2s2 2p6 3s2 3p6 4s2 3d7