# What is the electron configuration of the gallium ion?

Jun 8, 2016

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

#### 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.

Jul 5, 2016

The most common electron configuration for the gallium ion, ${\text{Ga}}^{3 +}$ is
$1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 3 {d}^{10}$ or $\left[\text{Ar}\right] 3 {d}^{10}$.

#### Explanation:

Gallium is in Group 13. It has 31 electrons.

Its electron configuration is $1 {s}^{2} 2 {s}^{2} 2 {p}^{6} 3 {s}^{2} 3 {p}^{6} 3 {d}^{10} 4 {s}^{2} 4 p$

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 $\text{Ga}$ would be to remove

• the $4 p$ electron and form ${\text{Ga}}^{+}$
• the $4 p$ electron and both $4 s$ electrons and form ${\text{Ga}}^{3 +}$.

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

So. the most common gallium ion is ${\text{Ga}}^{3 +}$, and its electron configuration is $\left[\text{Ar}\right] 3 {d}^{10}$.