Naming Inorganic Compounds To name a compound you must first decide whether the substance is an ionic or molecular compound. Ionic compounds are easily recognized since they usually contain both metallic and non-metallic elements. The most common exception to this rule are ionic compounds containing the ammonium ion, NH4+, such as (NH4)2CO3 or NH4Br which contain no metal ions. Molecular compounds typically contain only non-metallic atoms (and metalloids).