potassium 39

po·tas·si·um 39 (39K),

(pō-tas'ē-ŭm), Most abundant, nonradioactive isotope of potassium; accounts for 93.1% of natural potassium.

po·tas·si·um 39

(pŏ-tas'ē-ŭm) Most abundant, nonradioactive isotope of potassium; accounts for 93.1% of natural potassium.