A mole is Avogadro's number of any particle of definite composition. It is used to show the quantity of a substance that has a mass in grams numerically equal to its molecular mass. That mass contains Avogadro's number of molecules. It is the amount of a chemical substance that has a weight in grams which is equal to its molecular weight. One mole of a substance contains 6.023 x 10 ^23.

Potassium was discovered in October of 1807 by Sir Humphrey Davy. Davy had isolated Potassium by electrolysis. With its origin name of potash, potassium’s symbol is K. The origin of the symbol is from the Latin word kalium. In 1808, Gay-Lussac and Thenard devised a chemical method for production of large amounts of potassium and sodium. It involved a reaction of fused alkali with red hot iron turnings is a clay clad gun barrel. The freed metal vapor was collected and condensed.

Potassium has the atomic number of 19 and the atomic weight of 39.0983 (1). The seventh most abundant metal, Potassium makes up about 2.4% of the earth’s crust. With a melting point of 63.65 C and a boiling point of 774.0 C, it has a cubic crystal structure. Potassium is a alkali metal. It’s standard state is solid and has a color of silvery white. The atomic structure of potassium is that as follows.

Number of Energy Levels: 4

first energy level: 2

secondary energy level: 8

third energy level: 8

fourth energy level: 1

Potassium is an essential constituent for plant growth and is found in most plant soils. It has an important role in the regulation of osmotic potential of plant cells. If plants do not have enough potassium, curling and crinkling of the leaves may occur. The stems may be slender and weak. Roots may be susceptible to root-rotting fungi which is present in the soil. The weak stems and the contaminated soil can result in an increased tendency for the plant to be easily bent to the ground.

Potassium is never found free in nature. It is obtained by electrolysis of the chloride and/or hydroxide. Aside from Lithium, it is one of the most electropositive and reactive metal. Potassium has a silvery appearance immediately after fresh surface is exposed and is soft and easily cut with a knife. Potassium has a specific heat of 0.75 J/gK.

Potassium, like other metals of the alkali group, decomposes in water with the evolution of hydrogen. It oxidizes rapidly in the air and has to be stored under a suitable mineral oil or under argon. Potassium catches on fire unexpectedly in water and the salts that potassium contains add a lilac color to the flames.