11. The most abundant metal in the universe (and sixth most abundant element) is iron. The most abundant isotope of iron is 56Fe. Compute the minimum energy required to carry out each of following processes: (a) Remove one proton from a 56Fe nucleus. (b) Remove one neutron from a 56Fe nucleus. (c) Dismantle a56Fe nucleus into its component nucleons. (d) Split a 56Fe nucleus into two 28Al nuclei. 1.10. PROBLEMS 111 12. Although 56Fe is the most abundant metal in the universe, it is only the third most stable nuclide. The most stable nuclide is 62Ni : the second most stable nuclide is 58Fe. Compute the binding energy per nucleon for 62Ni, 58Fe, and 56Fe. 13. Terrestrial uranium ores consist of 99.28%U238 and 0.72%U235. However. it is thought that when first formed in a supernova, U235 is 1.650.15 times more abundant than U-238 (Weinberg 2008). Estimate the time that has elapsed since the formations of the uranium found in the earth's crust. 14. A fast breeder reactor initially contains 1 tonne of 239Pu and 2.5 tonnes of 238U. The reactor consumes 239Pu at a rate of 2.1kg/ day and operates at a breeding ratio of 1.12. Compute the following for this reactor: (a) Breeding gain; (b) Net plutonium production rate (kg/yr): (c) Doubling time (in years)