Specific activity

Specific activity is the radioactive activity of a sample per unit mass. In SI units, it is measured in becquerels per kilogram (Bq/kg).

Definition

The activity A of a sample is defined as

<math>A = \lambda N</math>

where N is the number of radioactive atoms in the sample and l is the decay constant. For a sample of mass m, the specific activity is simply A/m.