The electron configuration of 22X²+ ion is?

The electron configuration of $_{22} X^{2 +}$ ion is?

A. 1s² 2s²2p⁶ 3s² 3p⁶ 4s² 3d²
B. 1s² 2s²2p⁶ 3s² 3p⁶ 4s² 3d¹
C. 1s² 2s²2p⁶ 3s² 3p⁶
D. 1s² 2s²2p⁶ 3s² 3p⁶ 4s²

Correct Answer:

Option D – 1s² 2s²2p⁶ 3s² 3p⁶ 4s²

Explanation
$_{22} X^{2 +}$

$_{22} X^{2 +}$ has 22 electrons but has been ionized to 2+ by giving off 2 electrons. Hence, the ion $_{22} X^{2 +}$ has 20 electrons.

The electronic configuration = 1s² 2s²2p⁶ 3s² 3p⁶ 4s²