Question

The net charge on a sulfide ion, `"S"^(2-)`, is `2-`. How does this ion obtain its charge?

Answer 1

A neutral sulfur atom gains `2` electrons.

Explanation:

An ion can only be formed when a neutral atom gains or loses electrons.

Since electrons carry a negative charge, gaining electrons will result in the formation of a negatively charged ion, or anion. Similarly, losing electrons will result in the formation of a positively charged ion, or cation.

In your case, the sulfide anion, `"S"^(2-)`, carries a `(2-)` negative charge, which can only mean that it gained electrons.

More specifically, it gained `2` electrons. A neutral sulfur atom has an atomic number equal to `16`, which means that it has `16` protons inside its nucleus and `16` electrons surrounding its nucleus.

For each electron gained, the ion's overall charge decreases by `1` unit, which further confirms the fact that the neutral sulfur atom gained `2` electrons to get the `(2-)` charge.