Potassium ions

 Potassium ions are important in many biological processes. These are atoms of potassium, an alkaline metal, with an atomic number of 19 and symbol of K, that have lost their highest energy electrons to form a full outer shell. This gives them an electron configuration of  1s2 2s2 2p6 3s2 3p6, and a charge of plus one, donated by k⁺. 

In biological systems