19-K-40, (Kalium)
https://sites.google.com/view/isotope-evidence/19-k-40
https://en.wikipedia.org/wiki/Potassium#Isotopes
Naturally occurring 40K has a half-life of 1.250×10^9 years.
19-K-40, (Kalium)
https://sites.google.com/view/isotope-evidence/19-k-40
https://en.wikipedia.org/wiki/Potassium#Isotopes
Naturally occurring 40K has a half-life of 1.250×10^9 years.