what about the sulfur ion that is isoeletroinc with the neutral argon atom? what charge would this sulfur ion have

Question

what about the sulfur ion that is isoeletroinc with the neutral argon atom? what charge would this sulfur ion have

Answer 1

Sulfur ion has a charge of -2. You can know that because they are telling you that it is isoelectronic with neutral argon atom, which has 18 electrons. Since neutral sulfur has only 16 electrons then it most have gained 2 electrons in order to be isoelectronic (have the same number of electrons) with said Argon atom, gaining these 2 electrons makes it S^2-