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
Potassium bifluoride it to generate, for the first time, hydrogen fluoride. Potassium bifluoride is prepared by treating potassium carbonate or potassium hydroxide with hydrofluoric acid: The electrolysis of KHF was used by Henri Moissan to isolate the element fluorine in 1886. A related material containing two equivalents of HF is also known, KHF (CAS#12178-06-2, m.p. 71.7 C). The industrial production of fluorine entails the electrolysis of molten KHF. Potassium bifluoride Potassium bifluoride is the inorganic compound with the formula KHF. This colourless salt consists of the potassium cation and the bifluoride (HF) anion. The salt is used in etchant for glass. Sodium