Question

31.71 - Binding Energy 209Bi is the heaviest stable nuclide, and its BE/A is low compared with medium-mass nuclides. Calculate BE/A, the binding energy per nucleon, for 209Bi. (Compare it with the approximate value obtained from the graph in the figure below.) Enter your answer using 4 significant figures 2 6 Fe Zn Kr Mo Sm 7.6 238U He 150 200 Atomic mass 7.646 Mev Submi Answer Incorrect. Tries 1/10 Previous Tries

Answer 1

Atomic mass of Bi = 208.980388 u rightarrow m_1 Bi has 83 protons and 126 neutrons. Hence, the mass defect of this nucleus is Given as: Delta m^1 = (83 m_H + 126 m_n) - m_1 where, m_H = 1.007825 u m_n = 1.008665 u Delta m^1 = (83 times 1.007825 + 126 times 1.008665) - 208.980388 = 1.760877 u But, L u = 931.5 Mev/c^2 Therefore Delta m^1 c^2 = (1.760877 times 931.5) times c^2 times Mev/c^2 = 1640.26 Mev Therefore Average BE per nuclear = 7.848 Mev Hit like if you understood.