Question

which represents the ion formed when aluminum achieves a full valence shell?

Explanation:

Step1: Determine the valence electrons of aluminum

Aluminum (\(Al\)) has an atomic number of \(13\). Its electron configuration is \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{1}\). The valence shell (third shell) has \(3\) electrons.

Step2: Analyze how to achieve a full valence shell

To achieve a full valence shell (which has \(8\) electrons in the outermost shell for main - group elements, following the octet rule), it is easier for aluminum to lose \(3\) electrons rather than gain \(5\) electrons. When it loses \(3\) electrons, it forms a cation. The ion symbol for an aluminum ion that has lost \(3\) electrons is \(Al^{3 +}\).

Answer:

C. \(Al^{3+}\)