What sort of substances does berrylium form a covalent bond and with which substances is it ionic. i know that berrylium usually does form covalnt bonds, but sometimes i find it being referred to as an Be2+ ion. Also many berrylium compounds are good conductors of electricity such as berrylium chloride and this makes it sound ionic. So when is ionic and when is it covalent? Any help will be greatly appreciated!!!