Chemical element of metals. Cu comes from Cuprum, Fe comes from Ferrum, Ag from Argentum. The symbols were not followed by a period (full stop) as with abbreviations. Later chemical elements were also assigned unique chemical symbols, based on the name of the element, but not necessarily in English. For example, sodium has the chemical symbol 'Na' after the Latin "natrium". The same applies to "W" (wolfram) for tungsten, "Fe" (ferrum) for iron, "Hg" (hydrargyrum) for mercury, "Sn" (stannum) for tin, "K" (kalium) for potassium, "Au" (aurum) for gold, "Ag" (argentum) for silver, "Pb" (plumbum) for lead, "Cu" (cuprum) for copper, and
Chemical nomenclature of technical terms used in chemistry. Similar compendia exist for biochemistry (the "White Book", in association with the IUBMB), analytical chemistry (the "Orange Book"), macromolecular chemistry (the "Purple Book") and clinical chemistry (the "Silver Book"). These "color books" are supplemented by shorter recommendations for specific circumstances that are published periodically in the journal "Pure and Applied Chemistry". The primary function of chemical nomenclature is to ensure that a spoken or written chemical name leaves no ambiguity concerning which chemical compound the name refers to: each chemical name should refer to a single substance. A less important aim is to ensure