The two decay channels of potassium 40The decay scheme of potassium-40 is unusual.
The mass energy of atom is above these of its two neighbours in the family of atoms with 40 nucleons in their nucleus : Argon-40 with one proton less and calcium-40 with one proton more. The beta-minus decay channel leading to calcium_40 is by far the most frequent, but decays leading to argon-40 by electronic capture occurs at a rate of 11 %.
Argon 40, a gas held prisoner by lava The potassium-argon method is frequently used to date lava flows whose age is between a million and a billion years.
When an atom of potassium 40 decays into argon 40, the argon atom produced is trapped by the crystalline structure of the lava.
Radioactive elements are unstable; they breakdown spontaneously into more stable atoms over time, a process known as radioactive decay.
Radioactive decay occurs at a constant rate, specific to each radioactive isotope.
How can potassium 40 simultaneously have too many of both?