Sulfur (S) has 6 valence electrons (electrons in the outermost shell). To achieve a stable octet (8 electrons), it can either gain 2 electrons to become an anion with a -2 charge (S⁻²), or lose 6 electrons to become a cation with a +6 charge (S⁺⁶).

However, sulfur rarely forms a +6 cation due to the high energy required to remove six electrons. It's much more common for sulfur to form a -2 anion by gaining two electrons.

Therefore, sulfur typically gains 2 electrons to form an ion.