'''Activity''' is the rate of [[disintegration]] (transformation) or [[decay]] of [[radioactive]] material per unit time. The units of activity are the [[curie]] (Ci) and the [[becquerel]] (Bq). | '''Activity''' is the rate of [[disintegration]] (transformation) or [[decay]] of [[radioactive]] material per unit time. The units of activity are the [[curie]] (Ci) and the [[becquerel]] (Bq). |