Glossary
Artificial Radionuclide Background in French Metropolitan Territory

Radionuclide; radionuclide

Isotope of a chemical element whose radioactive nucleus decays. Examples: tritium, noted ³H, which is the radioactive isotope of hydrogen, or cesium 137 (¹³⁷Cs), which is one of the radioactive isotopes of cesium, are radionuclides.

Activité; activity

A quantity representative of a radionuclide. It corresponds to the number of disintegrations of radionuclide nuclei per unit of time, expressed in becquerels (Bq): 1 Bq = 1 disintegration per second.

Activités massique et volumique; massic or volumic activity

Quantities representative of the concentration of a radionuclide; they are expressed in Bq.kg^-1, Bq.L^-1, Bq.m^-3...

Radioactive period

Time required for the activity (quantity) of a radionuclide to be halved by its decay; the 9 radionuclides discussed in this article...