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  1. 1
    English · JMdict
    curie (unit of radioactivity)
    It was Marie Curie who discovered radium.
  2. 2
    English · Wikipedia

    The curie (symbol Ci) is a non-SI unit of radioactivity, named 'in honour of' Pierre Curie, according to his widow, the famed radiation researcher Marie Curie. It was originally defined as "the quantity or mass of radium emanation in equilibrium with one gram of radium (element)" but is currently defined as: 1 Ci = 3.7 × 1010 decays per second after more accurate measurements of the activity of 226Ra (which has a specific activity of 3.66 x 1010 Bq/g.) In 1975 the General Conference on Weights and Measures gave the becquerel (Bq), equal to one reciprocal second, official status as the SI unit of activity. Therefore: 1 Ci = 3.7 × 1010 Bq = 37 GBq and 1 Bq ≅ 2.703 × 10−11 Ci ≅ 27 pCi While its continued use is discouraged by National Institute of Standards and Technology (NIST) and other bodies, the curie is still widely used throughout the government, industry and medicine in the United States and in other countries. The curie is a large amount of activity, and was intentionally so. According to Bertram Boltwood, Marie Curie thought that 'the use of the name "curie" for so infinitesimally small (a) quantity of anything was altogether inappropriate.' The typical human body contains roughly 0.1 μCi (14 mg) of naturally occurring potassium-40. A human body containing 16 kg of carbon (see composition of the human body) would also have about 24 nanograms or 0.1 μCi of carbon-14. Together, these would have an activity of approximately 0.2 μCi or 7400 Bq inside the person's body.

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