Question

How does a Sulfur -2 ion differ from a neutral Sulfur atom?

Answer 1

Elemental sulfur, or sulfur in a neutral element has 6 electrons associated with it, and is therefore neutral. `S^(2-)` ions has 8 electrons, and therefore bears a 2- minus charge.

Explanation:

Sulfur in thioether, `R-S-R`, or `H_2S`, has 2 lone pairs and an electron from each of the bonds. When it's charge is determined these `6e^-` are balanced by the nuclear charge. In these situations sulfur is neutral. For `HS^-` or `S^(2-)`, there are 7 and 8 electrons associated with the respective sulfur centres, and these bear formal charges of `-1`, and `-2`.