Practice!

Sample Problem

Which compounds are not considered ionic?

SO3

LiF

MgCl2

CH4

H2O

Solution

Ionic bonds involve an attraction between cations (generally a metal) and anions (generally a nonmetal). Metal halides (LiF and MgCl2) are ionic compounds. The differences in electronegativity of the other compounds are not great enough for a transfer of electrons and so they are covalently bonded together.