For a given transition from an @E02257@ of a specified atom, the ratio of the number of excited atoms which emit a photon to the total number of excited atoms.
Source: PAC, 1994,
66, 2513. (
Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)) on page 2526 [
Terms] [
Paper]
See also: Orange Book, 2
nd ed., p. 174 [
Terms] [
Book]