Chemical nomenclature Therefore, the name of the compound is calcium hydroxide. If one is asked to write the formula for copper(I) chromate, the Roman numeral indicates that copper ion is Cu and one can identify that the compound contains the chromate ion (). Two of the 1+ copper ions are needed to balance the charge of one 2− chromate ion, so the formula is CuCrO. Type-III binary compounds are covalently bonded. Covalent bonding occurs between nonmetal elements. Covalently-bonded compounds are also known as "molecules". In the compound, the first element is named first and with its full elemental name. The second element
Naming of chemical elements after Amerigo Vespucci The non-transuranic element samarium is named after Vasili Samarsky-Bykhovets, and gadolinium is indirectly named (via the mineral gadolinite), after Johan Gadolin. Lecoq de Boisbaudran, who named the element gallium after his native land of France (from Latin "Gallia" meaning Gaul) denied that the element's naming was for a pun on his own name ("le coq" means "the rooster" in French, as does "gallus" in Latin). Some chemical elements are named after places on the planet earth. Five are named after currently existing countries – polonium (named after Poland), francium and gallium (named after France), nihonium (named after