# How can I write the formula for magnesium sulfide?

Jun 23, 2014

Magnesium Sulfide has a formula of $M g S$.

Magnesium is a metal cation with a charge of $M {g}^{+ 2}$
Sulfur is a nonmetal anion with a charge of ${S}^{- 2}$

In order to bond ionically the charges must be equal and opposite.
It will take one -2 sulfide ion to balance one +2 magnesium ion forming a magnesium sulfide molecule of $M g S$.