| Webster's Online Dictionary |
| Expressions | Domain | Definition | |
| Half-life period | Physics | 1: For a single radioactive decay process, the mean time required for the activity to decrease to half its value by that process. Source: European Union. (references) | |
| 2: The time taken for the concentration of the parent compound to be reduced to half its original value. It thus gives a measure of the persistence of the chemical in that particular soil. Source: European Union. (references) | |||
Source: compiled by the editor from various references; see credits. | Top | ||