Definition:Potassium
Jump to navigation
Jump to search
Chemical Element
Potassium is the chemical element that has $19$ protons in the nuclei of its atoms
Its chemical symbol is $\text K$.
Isotopes
K-$40$
Potassium-$40$ is the isotope of potassium which has $21$ neutrons in addition to its $19$ protons.
K-$40$ is radioactive, with a half-life of approximately $1.251 \times 10^9$ years.
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.