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
Mercury (element) of 46.612 days. Most of the remaining radioisotopes have half-lives that are less than a day. and are the most often studied NMR-active nuclei, having spins of and respectively. Hg is the modern chemical symbol for mercury. It comes from "hydrargyrum", a Latinized form of the Greek word ὑδράργυρος ("hydrargyros"), which is a compound word meaning "water-silver" (from ὑδρ- "hydr-", the root of ὕδωρ, "water," and ἄργυρος "argyros" "silver") – since it is liquid like water and shiny like silver. The element was named after the Roman god Mercury, known for his speed and mobility. It is associated with the