What is the name of MgO?

The name of MgO is Magnesium oxide, which is derived from the elements that compose it. In this compound, magnesium (Mg) is a metal from Group 2 of the periodic table, which typically forms a +2 oxidation state. Oxygen (O), being a nonmetal from Group 16, usually takes on a -2 oxidation state when it reacts to form ionic compounds.

When magnesium and oxygen combine, they form an ionic bond, and the compound is represented as MgO. The naming convention for ionic compounds generally involves naming the cation (the positively charged ion, in this case, magnesium) first, followed by the name of the anion (the negatively charged ion, oxygen), which is modified to end in "-ide." Therefore, the oxide ion (O²⁻) changes to "oxide," resulting in the name Magnesium oxide.

The other options include names that refer to different compounds. Magnesium acetate is an organic compound which features a different anion, while magnesium sulfide refers to the compound involving sulfur, and magnesium chloride involves chlorine. Each of these compounds has distinct properties and formulations, making Magnesium oxide the correct and appropriate name for MgO.