# How do you determine if a compound is ionic?

If it is a binary salt, $M X$, consider the positions of each element on the Periodic Table.
Alkali metals and alkaline earth metals comprise Group I and Group II on the Periodic Table. These are likely to form ionic salts with the common non-metals: the halogens and the chalcogens, as these are very likely to form ${X}^{-}$ and ${E}^{2 -}$ ions.