A former unit of measurement of radioactivity, replaced by the becquerel.
The unit of radioactivity prior to adoption of the becquerel. One curie is defined as 3.7 X 10¹º disintegrations per second.
Marie, the Polish-born Fr. chemist, 1867-1934, who discovered the radioactivity of thorium, discovered polonium and radium, and isolated radium from pitchblende. She was awarded the Nobel Prize in physics in 1903 with her husband, and in chemistry in 1911.
The quantity of a radioactive substance which has 3.7 X 1010 transitions, or disintegrations, per second. One gram of radium has almost exactly 3.7 X 1010 transitions per second. Thus 1 Ci of radium has a mass of almost exactly 1 g.
The measurement unit for radioactive substances, symbolizing the emanation equivalent to the radioactive emission from a source in which 3.7 x 10¹º atoms decay every second. This unit is named after Marie and Pierre Curie, the pioneers who discovered radium.