The net charge on a sulfide ion (s2-) explain how this ion obtains its charge your answer should include a discusion of subatomic particles

An ion must be shaped when a neutral atom picks up or loses electrons. 
Since electrons convey a negative charge, picking up electrons will bring about the formation of a contrarily charged ion, or anion. Thus, losing electrons will bring about the formation of an emphatically charged ion, or cation. 
For your situation, the sulfide anion, S^2−1, conveys a(2−) negative charge, which must imply that it picked up electrons. 
All the more particularly, it picked up 2 electrons. A neutral sulfur atom has an atomic number equivalent to 16, which implies that it has 16 protons inside its nucleus and 16 electrons encompassing its nucleus. 
For every electron picked up, the ion's general charge diminishes by 1 unit, which additionally affirms the way that the unbiased sulfur atom picked up 2 electrons to get the (2−) charge.