exponential decay

Variation of a quantity (generally the @[email protected] of a quantity of a @[email protected]) according to the law \(A=A_{0}\ \text{e}^{-\lambda\ t}\) where \(A\) and \(A_{0}\) are the values of the quantity being considered at time \(t\) and zero respectively, and \(\lambda\) is an appropriate constant.
PAC, 1982, 54, 1533. (Glossary of terms used in nuclear analytical chemistry (Provisional)) on page 1541 [Terms] [Paper]