Potassiu m argon dating
This article contains references to scientific journals and peer-reviewed research.The numbers in brackets correspond with the list of references at the end of the article.Although Potassium only has two stable isotopes (K-39 and K-41), the long-lived radioisotope K-40 is often also regarded as a stable isotope.
It is essential for the growth of plants and is used especially in fertilizers and soaps.
The silvery white metal is soft (easily cut with a knife). An alloy of potassium and sodium is used as a heat transfer medium. Sources: Potassium is the 7th most abundant element on earth, making up 2.4% of the earth's crust, by weight. Potassium was the first metal isolated by electrolysis (Davy, 1807, from caustic potash KOH).
The metal must be stored in a mineral oil, such as kerosene, as it oxidizes rapidly in air and catches fire spontaneously when exposed to water. Thermal methods (reduction of potassium compounds with C, Si, Na, Ca C) are also used to produce potassium.
This is not to be confused with the relative percentage isotope abundances which totals 100% for all the naturally occurring isotopes.
Further data for naturally occuring isotopes of potassium are listed above.