https://doi.org/10.1351/goldbook.E02275
Variation of a quantity (generally the @A00114@ of a quantity of a @R05116@) 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.