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
Cobalt(II) nitrate or one of its oxides, hydroxides, or carbonate with nitric acid: Cobalt(II) nitrate Cobalt Nitrate is the Inorganic compound with the formula Co(NO3)xHO. It is cobalt(II) salt. The most common form is the hexahydrate Co(NO)·6HO, which is a red-brown deliquescent salt that is soluble in water and other polar solvents. As well as the anhydrous compound Co(NO), several hydrates of cobalt(II) nitrate exist. These hydrates have the chemical formula Co(NO)·"n"HO, where "n" = 0, 2, 4, 6. Anhydrous cobalt(II) nitrate adopts a three-dimensional polymeric network structure, with each cobalt(II) atom approximately octahedrally coordinated by six oxygen atoms, each from a