What do the following have in common: MgCl2, AlF3, CaI2, KCl
Choose all that apply.
They are nonpolar in nature.
They are salts.
They are all ionic compounds.
They are all molecular compounds.

They are salts, ionic compounds

Explanation:

To know if they are covalent or ionic we need to check their difference in electronegativity. As an example mgcl2, mg has electronegativity of 1.2 and cl 3 so 3-1.2=1.8 which is bigger than 1.7 means it's ionic therefore they are salts