Nuclear Stability
The tendency of a nucleus to persist without undergoing radioactive decay.
Unit
Dimensionless
In depth
Stability depends on the neutron-to-proton ratio, on the total nucleon count and on whether the proton and neutron numbers are even. Even–even nuclei are markedly more stable than odd–odd ones, and no nuclide above bismuth-209 is stable at all.
Examples in the real world
Of the 250-odd stable nuclides, more than half have both an even proton and an even neutron count.