Any compound produced by the combination of a halogen, such as chlorine or iodine, with a less electronegative element (see electronegativity). Halides may be formed by ionic bonds (such as common table salt, sodium chloride) or by covalent bonds (such as alkyl halides, organic molecules consisting of a halogen and an alkyl group, such as methyl chloride (chloromethane).
The emblem reflects the Vatican's importance as the headquarters of the Roman Catholic Church. The colours of the flag are based on the gold and silver of the papal keys. Effective date: 8 June 1929.