What is a “curie” of radiation?
A curie is the amount of a pure radio-nuclide which can decay into a different substance at the rate of 37 billion atoms per second. Decay means changes in the atomic nucleus. The curie is not a measure of biological dose. The dose (in rads) is a separate piece of information. Each pure radioactive species is characterized by what fraction of its remaining atoms are decaying during a unit of time (second, minute, year). The radioactive half-life is the time required for half of the atoms in any pure radioactive sample to decay into a different species.
