What is the chemical formula for magnesium chloride?

The chemical formula for magnesium chloride is represented as MgCl₂. This formula indicates that each magnesium (Mg) atom combines with two chloride (Cl) ions. Magnesium has a +2 charge as a metal cation, and chloride is a nonmetal with a -1 charge. The two negative charges from the two chloride ions balance the positive charge from one magnesium ion, resulting in a neutral compound. This stoichiometry is essential for determining the correct chemical formula, which reflects the ratio of magnesium to chloride in the compound.

Other options represent different compounds with distinct combinations of metals and halogens. Calcium chloride (CaCl₂) features calcium, sodium chloride (NaCl) contains sodium, and potassium chloride (KCl) is made with potassium, each differing in their respective metal and the number of chloride ions they bond with, highlighting the specificity of the elements involved in creating magnesium chloride.