Question

What is the electron configuration of the gallium ion?

Answer 1

The electron configuration for Gallium, Ga is
`1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 4p^1`

Explanation:

Gallium, Ga has 31 protons and 31 electrons. The superscripts represent the electrons present in each region of the periodic table.
The sum of these superscripts should equal the atomic number for a neutral atom. The last electron is in the 4th period, in the p region and the first electron in that region.

Answer 2

The most common electron configuration for the gallium ion, `"Ga"^(3+)` is
`1s^2 2s^2 2p^6 3s^2 3p^6 3d^10` or `["Ar"] 3d^10`.

Explanation:

Gallium is in Group 13. It has 31 electrons.

Its electron configuration is `1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 4p`

We form cations by removing electrons first from the outermost `p` orbitals, followed by the `s` orbital and finally the `d` orbitals (if any more electrons need to be removed).

The options for `"Ga"` would be to remove

• the `4p` electron and form `"Ga"^+`
• the `4p` electron and both `4s` electrons and form `"Ga"^(3+)`.

By far the most common ion of Group 13 metals is +3.

So. the most common gallium ion is `"Ga"^(3+)`, and its electron configuration is `["Ar"] 3d^10`.