Question

Write the complete electron configuration for gallium using the periodic table.

Express your answer in complete form, in order of increasing orbital. For example, 1s²2s² would be entered as 1s²2s².

Answer 1

The complete electron configuration for gallium (Ga) is [Ar]4s² 3d¹⁰ 4p¹. The sequence follows the order of the orbitals from the 1s to the 4p, commencing with the inert gas configuration for argon. Gallium's stability in forming ions is due to its filled 3d¹⁰ subshell, and it forms a stable Ga³+ ion.

Step-by-step explanation:

To write the complete electron configuration for gallium (Ga), you must begin at the 1s orbital and proceed in order of increasing energy according to the periodic table. Ga is located in the 4th period and is part of the p-block elements, following the first row of transition metals. Therefore, its electron configuration starts with the noble gas core of argon ([Ar]) before adding the electrons for the outer orbitals.

The configuration for Ga can be written as:

1. Fill the 1s orbital with two electrons: 1s².
2. Add two electrons to the 2s orbital: 2s².
3. Place six electrons in the 2p orbitals: 2p⁶.
4. Next, add two electrons to the 3s orbital: 3s².
5. Then six electrons go into the 3p orbitals: 3p⁶.
6. Add two electrons to the 4s orbital, which are higher in energy than 3d: 4s².
7. Place ten electrons in the 3d orbitals, completing this subshell: 3d¹⁰.
8. Finally, place one electron in the 4p orbital: 4p¹.

So, the full electron configuration for Ga is [Ar]4s² 3d¹⁰ 4p¹.

Electron Configuration Stability

The filled 3d¹⁰ subshell provides a level of stability, and when forming ions, Ga usually loses electrons from the 4s² orbital before the 3d¹⁰, leading to a Ga³+ ion with a stable electron configuration similar to a noble gas.