Warning (2): get_headers(): https:// wrapper is disabled in the server configuration by allow_url_fopen=0 [APP/Controller/TermsController.php, line 315]
Warning (2): get_headers() [<a href='http://php.net/function.get-headers'>function.get-headers</a>]: This function may only be used against URLs [APP/Controller/TermsController.php, line 315]
IUPAC - half life (H02717)

half life

of a radionuclide
Synonym: radioactive half life
https://doi.org/10.1351/goldbook.H02717
For a single @R05083@ process, the time required for the activity to decrease to half its value by that process.
Source:
PAC, 1994, 66, 2513. (Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)) on page 2520 [Terms] [Paper]