<p>Potassium 39 is a stable isotope as is the K41. K40 is an unstable isotope, however its decay rate (half-life) is a Billion years or so.</p>
<p>K40 will have another 'neutron'/proton and it is not difficult to see how that would result in a second Lithium nuclet turning the K40 into Ca40. </p>
Atomic Structure
N0:
state: final
protons:
P0:
P1:
P2:
P3:
P4:
P5:
P6:
P7:
P8:
P9:
P10:
P11:
nuclets:
N00:
state: lithium
attachAngle: 3
protons:
P1:
P3:
P4:
P5:
P9:
P11:
N01:
state: final
attachAngle: 3
protons:
P0:
P1:
P2:
P3:
P4:
P5:
P6:
P7:
P8:
P9:
P11:
P12:
P13:
P14:
P15:
P16:
P17:
P18:
P19:
neutrons: [U00, U10]
Notes
<p>This is due to the fact that the 2 extra protons on the Beryllium nuclet ending are every now and then drawn into the neutral ending to create a 5 neutral ending. Most likely this kind of 'decay' has an external cause. (there can be an internal and external cause for this kind of nuclear 'decay') K 40 / Ca 40 and Ar 40 are transmutable into each other depending obviously on circumstances. Life ! most likely IS capable of using this phenomena and is related to the "missing noble gasses problem". </p>