Question

Which element is most likely to form an anion with a -2 charge?

(a) S
(b) As
(c) Be
(d) Al

Answer 1

Sulfur (S) is most likely to form an anion with a -2 charge as it commonly gains two electrons to achieve a noble gas electron configuration, resulting in a sulfide ion (S2-).

Step-by-step explanation:

The element most likely to form an anion with a -2 charge is S, sulfur. When atoms form ions, metals typically lose electrons to become cations, whereas nonmetals typically gain electrons to become anions. Sulfur, being in Group 16 of the periodic table, commonly gains two electrons to complete its valence shell to become S2-, a sulfide ion. This is a desired state as atoms strive to achieve a noble gas electron configuration. In contrast, elements like beryllium (Be) would form cations with a +2 charge, and arsenic (As) typically forms a -3 charge when it becomes an anion. Aluminum (Al) forms a cation with a +3 charge.

In terms of electron configuration, after sulfur (S) gains two electrons, it takes on the configuration similar to argon, becoming S2- with an electron configuration of [Ne] 3s2 3p6.