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 pyrosulfate Potassium pyrosulfate Potassium pyrosulfate, or potassium disulfate, is an inorganic compound with the chemical formula KSO. Potassium pyrosulfate is obtained by the thermal decomposition of other salts, most directly from potassium bisulfate: Temperatures above 600°C further decompose potassium pyrosulfate to potassium sulfate and sulfur trioxide however: Other salts, such as potassium trisulfate, can also decompose into potassium pyrosulfate. Potassium pyrosulfate contains the pyrosulfate anion which has a dichromate like structure. The geometry can be visualized as a tetrahedron with two corners sharing the SO anion's configuration and a centrally bridged oxygen atom. A semi-structural formula for the pyrosulfate anion is