radioactive equilibrium

https://doi.org/10.1351/goldbook.R05084
Among the members of a
decay chain
, the state which prevails when the ratios between the
activities
of successive members remain constant. (This is not an equilibrium in the strict sense since
radioactive decay
is an irreversible process).
Source:
PAC, 1994, 66, 2513. (Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)) on page 2519 [Terms] [Paper]