Units of Radioactivity

 The standard unit in radioactivity is curie (c) which is defined as that amount of any radioactive material which gives  disintegration’s per second (dps), i.e.,1c = Activity of 1g of 

The millicurie (mc) and microcurie (mc) are equal to  and  curies i.e.  and dps respectively.

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But now a day, the unit curie is replaced by rutherford (rd) which is defined as the amount of a radioactive substance which undergoes  i.e., . The millicurie and microcurie correspondingly rutherford units are millirutherford (mrd) and microrutherford (mrd) respectively.

However, in SI system the unit of radioactivity is Becquerel (Bq)

1 Bq = 1 disintegration per second = 1 dps = 1mrd, ,