The beta electrons of the decay into calcium 40 (89.3% of the time) are not accompanied by gamma rays, and are generally absorbed into the medium they find themselves in.
IN2P3Stable nuclei sit at the bottom of a so-called ‘valley of stability’, a concept that helps determine whether a nucleus is radioactive or not.
From potassium 40 to argon 40The electron capture which causes potassium 40 to transform into argon 40 in its ground state takes place in only 0.04% of cases.
The poster also discusses other Fermi findings, including a black widow pulsar, the Fermi Bubbles rising thousands of light-years out of our galaxy's center, a giant gamma-ray flare from the Crab Nebula, and many more.
This difference is enough to make potassium 40 unstable.
The reason for this is that protons, like neutrons, like to exist in pairs in a nucleus.
Potassium 40 should be at the bottom of this valley and should be the most stable of the nuclei containing 40 nucleons.
Its mass energy (or internal energy), however, is actually greater than either of its neighbours – calcium 40 and argon 40.
In both argon 40 and calcium 40, however, the number of protons and neutrons are even, granting them that extra stability.