Potassium undergoes tarnishing when exposed to air and oxygen. At standard conditions, potassium can be cut with a knife. Potassium is silvery-white, soft metal with second least density (0.89 g/cm 3). Potassium is also present in fruits (high concentrations in bananas, avocadoes), vegetables (potatoes, tomatoes, beet green, white beans), fish and meat. It is a major component of variety of proteins and enzymes. In human body, potassium constitutes about 0.2% by mass and is about the 8 th most abundant element of human biological system. Potassium is also present in Supernovae environment and produced through explosive oxygen-burning process. It has a low first ionization energy (418.8 kL/mol). It is also found in dissolved form in sea water and constitute about 0.04% potassium by weight. In ratio of abundance, it is the 20 th most abundant element in the solar system and 17 th most abundant on the earth (makes around 2.6% of weight of the earth’s crust). Potassium occurs in nature in the form of ionic salts. The symbol of potassium is K and is derived from kali (alkali), which is derived from Arabic work for plant ashes ( al-qalyah). It was first obtained in pure form by Humphry Davy (1807), through the process of electrolysis. the mixture was heated and the solution by evaporated to obtain potash (potassium). In early days, potassium was extracted by placing ashes of burnt tree in a pot along with water. Potassium was discovered from the ashes of plants and its name was derived from potash (plant ashes).

It is a biologically essential element and also has various industrial applications, including fertilizers, pesticides, explosives etc. Potassium is an alkali metal and was obtained in pure elemental form in 1807 by Hymphry Davy.

Potassium element configuration