Question

Write the electron configurations for the following ions:

Answer 1

Answer:

Co²⁺ : 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁷

Sn²⁺ : 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰

Zr⁴⁺ : 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶

Ag⁺ : 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 4d¹⁰

S²⁻ : 1s² 2s² 2p⁶ 3s² 3p⁶

Explanation:

Cobalt (Co): atomic number 27

The electronic configuration of Co in ground state:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁷

The electronic configuration of Co in +2 oxidation state (Co²⁺) :

1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁷

Tin (Sn): atomic number 50

The electronic configuration of Sn in ground state:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p²

The electronic configuration of Sn in +2 oxidation state (Sn²⁺) :

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰

Zirconium (Zr): atomic number 40

The electronic configuration of Zr in ground state:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d²

The electronic configuration of Zr in +4 oxidation state (Zr⁴⁺) :

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶

Silver (Ag): atomic number 47

The electronic configuration of Ag in ground state:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ 4d¹⁰

The electronic configuration of Ag in +1 oxidation state (Ag⁺) :

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 4d¹⁰

Sulphur (S): atomic number 16

The electronic configuration of S in ground state:

1s² 2s² 2p⁶ 3s² 3p⁴

The electronic configuration of S in -2 oxidation state (S²⁻) :

1s² 2s² 2p⁶ 3s² 3p⁶

Answer 2

Answer:

Co⁺²: 1s²2s²2p⁶3s²3p⁶3d⁷

Sn²⁺: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰

Zr⁴⁺: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶

Ag⁺: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s¹4d⁹

S²⁻: 1s²2s²2p⁶3s²3p⁶

Explanation:

The electronic configuration is the distribution of the electrons through the orbitals, which are represented by the levels (by numbers) and sublevels (by letters) in the energetic order, which is determined by the Linus Pauling's diagram (which is shown below).

The sublevels maximum number of electrons is:

s = 2, p =6, d= 10, and f = 14.

To do the configuration of ions, we must first do it for the neutral atom (number of electrons = atomic number), and then if it is a cation (positive charge), remove electrons from the valence sublevel (most energetic), and if it's an anion, to added electrons to the most energetic sublevel.

Co⁺²

Neutral atom: Co

Atomic number: 27

Electron configuration of neutral atom:

1s²2s²2p⁶3s²3p⁶4s²3d⁷

In this case, because the atom is a transition metal, the electrons must be removed from the 4s sublevel, and not from the 3d sublevel, because the ion will be more stable if the electrons are removed from the valence shell. So, 2 electrons must be removed (+2).

Ion configuration:

1s²2s²2p⁶3s²3p⁶3d⁷

Sn²⁺

Neutral atom: Sn

Atomic number: 50

The electron configuration of neutral atom:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p²

Two electrons must be removed from the most energetic subshell (5s).

Ion configuration:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰

Zr⁴⁺

Neutral atom: Zr

Atomic number: 40

The electron configuration of neutral atom:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d²

It must lose 4 electrons. So, it will lose the 2 electrons of 5s (as explained above for Co), and the 2 electrons of 4d, because after that it will be the most energetic sublevel.

Ion configuration:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶

Ag⁺

Neutral atom: Ag

Atomic number: 47

The electron configuration of neutral atom:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d⁹

It must lose 1 electron, so, as explained above, it must be removed from 5s.

Ion configuration:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s¹4d⁹

S²⁻

Neutral atom: S

Atomic number: 16

The electron configuration of neutral atom:

1s²2s²2p⁶3s²3p⁴

It must gain 2 electrons (2-), which will be added to the most energetic sublevel, 3p.

Ion configuration:

1s²2s²2p⁶3s²3p⁶