Potassium in 1809, Ludwig Wilhelm Gilbert proposed the name "Kalium" for Davy's "potassium". In 1814, the Swedish chemist Berzelius advocated the name "kalium" for potassium, with the chemical symbol "K". The English and French speaking countries adopted Davy and Gay-Lussac/Thénard's name Potassium, while the Germanic countries adopted Gilbert/Klaproth's name Kalium. The "Gold Book" of the International Union of Physical and Applied Chemistry has designated the official chemical symbol as K. Potassium is the second least dense metal after lithium. It is a soft solid with a low melting point, and can be easily cut with a knife. Freshly cut potassium is
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