How do you determine if a compound is ionic?

1 Answer
Jul 8, 2016

If it is a binary salt, #MX#, consider the positions of each element on the Periodic Table.


Does the metal come from the far left of the Periodic Table (as we face it)? Does the non-metal come from the right of the Periodic Table. If so, the compound is likely ionic.

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.

Are the metals and non-metals closer together on the Periodic Table? Their compounds might have some measure of covalency.