#radioactivity_unit__radioactivityunit  a measure of radioactivity
  supertype:  pm#radioactivity_measure (pm)  #electromagnetic_unit
  subtype:  #millicurie  a unit of radioactivity equal to one thousandth of a curie
  subtype:  #curie__Ci  a unit of radioactivity equal to the amount of a radioactive isotope that decays at the rate of 37,000,000,000 disintegrations per second
  subtype:  #roentgen__R  a unit of radiation exposure; the dose of ionizing radiation that will produce 1 electrostatic unit of electricity in 1 cc of dry air
  subtype:  #rutherford  a unit strength of a radioactive source equal to one million disintegrations per second
  subtype:  #REM__rem  (Roentgen Equivalent Man) the dosage of ionizing radiation that will cause the same amount of injury to human tissue as 1 roentgen of X-rays
  subtype:  #rad  a unit of absorbed ionizing radiation equal to 100 ergs per gram of irradiated material

1 statement is about a direct instance of #radioactivity_unit: pm#graph1_on_radiation
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