Worlds of David Darling
Encyclopedia of Science
Home > Encyclopedia of Science

curie (Ci)

The curie (Ci) is a unit formerly used to measure the activity of a radioactive substance (see radioactivity). Named after Marie Curie, it is defined as that quantity of an isotope that decays at the rate of 3.7 × 1010 disintegrations per second. The curie has been replaced by an SI unit, the much smaller becquerel.

Related entry

   • activity