Question

Could someone help me with question 2a) and also help with b), I can do 2b) but I am wondering when do I use Ap = 0 or +/-11.2. Many thanks in advance.

Q.2 Answer all parts. (a) Explain the origin and mathematical form of each term in the Weizslicker semi-empirical mass formula for the binding energy, B, of a nucleus, Le. Z(Z-1) (A-2Z B- +a, A - a A where A is the atomic mass number of the nucleus and Z is the atomic number of the nucleus. 110 marks) (b) A fit of the Weizsäcker semi-empirical mass formula to binding-energy data for heavy nuclei yields the following values for the parameters in the formula: av = 15.8 MeV; as = 17.8 MeV; ac" 0.711 MeV; ap"-23.7 MeV; ap 0,+11.2 MeV (as appropriate). (i) Calculate the binding energies of americium-241 ( neptunium-237 Np). Am ) and 14 marks] (ii) Calculate the O-value for the alpha decay of americium-241 to neptunium-237. (Note: An a-particle has a binding energy of 28.3 MeV.) 2 marks (c) The ground state of an americium-241 nucleus has a spin-parity of 5/2 while the energy levels and spin-parities of the nuclear ground state and first few excited states of neptunium-237 are shown in the diagram below. (i) Identify the state in the diagram to which americium-241 is most likely to decay via a-decay? Give a very brief explanation for your answer. 2 marks) (ii) Calculate the kinetic energy of the a-particle resulting from that decay 2 marks 5th (0.159 MeV) 9/2 4th (0.103 MeV) - 7/2 3rd (0.073 MeV) 9/2"