t1/2 = Half-life of the isotope; T = Time taken for the specific decay ; Wini = Initial amount of the radioactive isotope; Wfin = Final amount of the radioactive isotope
t1/2 = Half Life of Radioactive elment; λ = Decay Constant of the radioactive element
λ = Radioactive Decay Constant or Disintegration Constant; t = Time interval for which radioelement is present ;
n0 = Initial number of atoms ; n= Final number of atoms.
A = Mass number; Z= Atomic Number = Number of protons present in the nucleus