Curie (unit)

Physical unit
Unit name	curie
Unit symbol	${\displaystyle \mathrm {Ci} }$
Physical quantity (s)	activity
Formula symbol	${\displaystyle A}$
dimension	${\displaystyle {\mathsf {T^{-1}}}}$
In SI units	${\displaystyle \mathrm {1\;Ci=37\,GBq} }$ ${\displaystyle \mathrm {=3{,}7\cdot 10^{10}\;s^{-1}} }$
Named after	Marie and Pierre Curie
Derived from	Activity of radium -226
See also: Becquerel

Curie is the obsolete unit of activity of a radioactive substance with the symbol Ci; it was used temporarily until 1985, when it was replaced by the SI unit Becquerel . Today it is only used in materials testing. 1 curie was originally defined as the activity of 1 g of radium -226, and later set to the approximately same value of 3.7 · 10 ¹⁰  Becquerel (= 37 GBq).

The unit was named after Marie and Pierre Curie who, together with Antoine Henri Becquerel, received the Nobel Prize for the discovery of radioactivity in 1903 .