The binding energy of a nucleus with atomic number z and atomic mass number A is given by semi-empirical mass formula B(2. A)=a4-b43_c(4-2) where, a = 15.8 MeV. b = 18.3 MeV, c = 23.2 MeV. d = 0.7 MeV and 6 =(+11.2, 0, -11.2) MeV for nuclei which are (odd-odd, odd-even, even-even). If we consider all possible isobars of mass number 216, the most stable nuclei is 216 82 Pb O216 87 O 216 Fr -2 A/3 85 At 8 A1/2 -d- O 216 86 Rn