'''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).
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'''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).