Meanings
nounpotassium-40 (uncountable)
- uncountablenatural sciencesA naturally-occurring radioactive isotope of potassium, 4019K, having 19 protons and 21 neutrons, and a half-life of 1.3 billion years; it is the chief source of natural radioactivity in living tissue
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APA
potassium-40. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/potassium-40
MLA
“potassium-40.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/potassium-40. Accessed November 4, 2026.
Chicago
WatkinsX Dictionary, s.v. “potassium-40,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/potassium-40.
Source: potassium-40 on Wiktionary, CC BY-SA 4.0.