• Question: What's potassium??

    Asked by gmsv to Melanie, David on 18 Mar 2011 in Categories: .
    • Photo: David Pyle

      David Pyle answered on 16 Mar 2011:

      Potassium, K, is a group I (alkali) metal from the fourth row of the periodic table, with atomic number 19 and an atomic mass of about 39. It is the seventh most abundant element in the Earth’s crust, but only about the 17th most abundant element in the Earth as a whole. K has three naturally occurring isotopes (39, 40 and 41). K-40 is radioactive, decaying to Ar-40 and Ca-40, with a half-life of about 1.2 billion years. K-40 is an important radioactive heat source inside the Earth, along with U and Th. K-Ar dating is an important tool in Earth sciences.

    • Photo: Melanie Stefan

      Melanie Stefan answered on 18 Mar 2011:

      A chemical element, found in bananas.

Comments