Page 195 - Radiation Safety

Definition and Unit of Radioactivity

• Definition – the property of certain nuclides of spontaneously emitting
ionising radiation

• Nuclide called radionuclide or radioisotope for the same element

• Radionuclide activity - a measure of the number of nuclear

transformations taking place every second

• Unit - Becquerel (Bq) = one nuclear disintegration per second

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