becquerel
SI derived unit of radioactivity equal to one disintegration per second; admitted for reasons of safeguarding human health, symbol: Math - text.
Source:
Green Book, p. 72
PAC, 1994, 66, 2513 (Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)) on page 2516
PAC, 1996, 68, 957 (Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)) on page 963