Radioactivity (radioact.) - Dynamic NPU Manual

Radioactivity (radioact.)



Definition in words

Number of nuclear decays occurring in a given quantity of material in a small time interval, divided by the duration of that time interval (ref 3)

The property of certain nuclides showing radioactive decay (ref 1)

Definition by equation

Systematic terms

Radioactivity of component B in system 1
Ratio scale
  • Value sets are positive numerical values
  • Algebraic operations are allowed (a=nb; a≠nb)
Numerical values from 0-∞


Bq, kBq

Non-recommended term

Hydrostatic volumic energy, hydraulic pressure, hydrostatic pressure


  1. IUPAC Goldbook
  2. SI Brochure
  3. Lehmann HP, Fuentes-Arderiu X, Bertello L. Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996). Pure and Applied Chemistry. 2009;68(4):957-1000. doi:10.1351/pac199668040957.
  4. Ferard G, Dybkaer R, Fuentes-Arderiu X. Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences : Recommendations 2016. 1 ed: Royal Society of Chemistry; 2016. 182 p.


Laboratory field


Clinical Chemistry

Generic abbreviated
NPU13810 Pt—58Co-Cobalamin(administered); radioact.(p.o.) = ? kBq
Full result NPU13810 Patient—58Co-Cobalamin(administered); radioactivity(oral administration) = 25 kilobecquerel
Abbreviated result NPU13810 Pt—58Co-Cobalamin(administered); radioact.(p.o.) = 25 kBq
Written expression The radioactivity of oral 58Co-Cobalamin administered to Mr. Smith [25] kBq.


  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Rational unitary kind-of-quantity

          • Radioactivity


  • Dybkaer R. Concept system on ‘quantity’: formation and terminology. Accredit Qual Assur. 2013;18(3):253-60.
  • Dybkaer R. ISO terminological analysis of the VIM3 concepts ‘quantity’ and ‘kind-of-quantity’. Metrologia. 2010;47(3):127-34.
Date Term Note
1996-01-01 Radioactivity Term established