## Wikipedia - تضاؤل أسي (ar) exponential decay

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.
Source:
PAC, 1982, 54, 1533. (Glossary of terms used in nuclear analytical chemistry (Provisional)) on page 1541 [Terms] [Paper]