Answer is: MgF₂, magnesium fluoride.
Magnesium fluoride is salt, ionic compound, because magnesium is metal from 2. group of Periodic table of elements and has low ionisation energy and electronegativity, which means it easily lose valence electons, fluorine is nonmetal with greatest electronegativity, which meand it easily gain electron, so magnesium cation (Mg²⁺) and fluorine anion (F⁻) are formed.