decay constant

https://doi.org/10.1351/goldbook.D01538
Proportionality constant relating the activity of a @[email protected] substance, A, to the number of decaying particles B, $$N_{\text{B}}$$, $$A=\lambda \ N_{\text{B}}$$. @[email protected] of a @[email protected] within a time interval divided by that time interval. Synonymous with @[email protected]
Source:
Green Book, 2nd ed., p. 22 [Terms] [Book]