begin mathsize 36px style t subscript bevelled 1 half end subscript space. space log open parentheses W subscript i n i end subscript over W subscript F i n end subscript close parentheses space equals space T space. space log left parenthesis 2 right parenthesis space end style

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

begin mathsize 48px style t subscript bevelled 1 half end subscript equals space 0.693 divided by lambda end style

t1/2 = Half Life of Radioactive elment; λ = Decay Constant of the radioactive element

begin mathsize 36px style lambda equals fraction numerator 2.303 over denominator t end fraction log open parentheses n subscript 0 over n close parentheses end style

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.

begin mathsize 36px style Z equals fraction numerator 38 A over denominator 0.6 A to the power of begin display style bevelled 2 over 3 end style end exponent plus 76 end fraction end style

A = Mass number; Z= Atomic Number = Number of protons present in the nucleus