Definition:Potassium

Chemical Element
Potassium is the chemical element that has $19$ protons in the nuclei of its atoms

Its chemical symbol is $\text K$.

Linguistic Note
The word potassium derives from the word potash, from which potassium was first extracted.

Potash is a general name for the salts of potassium, manufactured in pre-industrial times from the ash of plants, processed in a pot.

Its symbol $\text K$ derives from the neo-Latin kalium, itself deriving from the Arabic word القَلْيَه‎ (al-qalyah) meaning plant ashes.