(C, c, Ci) Curie is an obsolete unit of radioactivity; superseded by the SI unit becquerel.
1 curie is 3.70 x10¹⁰ disintegrations per second or 37,000 MBq. Formerly it was defined as the radiation emitted by 1 g of radium.
The curie is originated on Marie (1867-1934) and Pierre (1859-1906) Curie, (French chemists and physicists and Nobel laureates).

See Becquerel.

(mCi) One thousandth of a curie.

See Curie.

(Bq) Becquerel is the system international (SI) since 1985 new unit of radioactivity. 1 becquerel is equal to 1 disintegration per second.
1 Bq = 0.027 x10^-9 Ci (Curie).
In medicine and radiation protection the SI measurement units of becquerel, gray and sievert (should) have replaced the conventional units of curie, rad and rem.

To convert:


See also Gray, Sievert, Roentgen Equivalent In Man, Radiation Absorbed Dose, Count and Becquerel Antoine Henri.

Activity is the rate of radioactive decay or the emission rate of a radiation from radioactive material. The cumulated activity is useful for nuclides that emit multiple radiations per disintegration.
The units for activity are the curie (Ci) and the becquerel (Bq).