the rate of radioactive decay of a nuclide, expressed by (chance of decay/time).
For an atom that undergoes radioactive decay, the decay constant is the proportionality factor between the time rate of decay and the total number of atoms present; it is the inverse of the mean lifetime of an atom. A to F | G to L | M to R | S to Z
the fraction of a number of atoms of a radioactive nuclide that disintegrates in a unit of time. The decay constant is inversely proportional to the radioactive half-life.
(of a radioisotope) The proportion of the number of atoms that decay each second.
The fraction of the number of atoms of a radioisotope which decay in a unit time. It is expressed as the reciprocal of time (e.g. seconds-) and is related to the half-life by the following equation: .
It is the constant C in the equation (I=I0e-ct) to determine the half life of radioactive material.
A constant, , not to be confused with wavelength, that defines the speed at which a radioactive element undergoes decay. The greater is, the faster the element decays.