A compound of a halogen with another element or group. The halides of typical metals are ionic (e.g. sodium fluoride, Na⁺F⁻). Metals can also form halides in which the bonding is largely covalent (e.g. aluminium chloride, AlCl₃). Organic compounds are also sometimes referred to as halides; e.g. the alkyl halides (see haloalkanes) and the acyl halides. Halides are named fluorides, chlorides, bromides, or iodides.