Quantum Physics

1004 Chapter 30 Nuclear Energy and Elementary Particles18. A typical chemical reaction is one in which a water 19. The neutral meson decays by the strong interaction1event such as 0 n 23592 U : 13653 I 9839 Y 21 0 n . K 0 : , but with a much longer half-lifeWould you expect the energy released in this nuclearof about 10 10 s. How do you explain these obser-molecule is formed by combining hydrogen andinto two pions according to : ,oxygen. In such a reaction, about 2.5 eV of energy with a half-life of about 10 23 s. The neutral Kis released. Compare this reaction to a nuclear meson also decays into two pions according toevent to be much greater, much less, or vations?about the same as that released in the chemical reaction?Explain.PROBLEMSthat each fission produces 200 MeV of thermal1, 2, 3 straightforward, intermediate, challenging full solution available in Student Solutions Manual/Study Guide coached problem with hints available at www.cp7e.com = biomedical applicationSection 30.1 Nuclear Fissionn 23592 U : 98 13540Zr 52 Te 3n engine has an efficiency of 20%? (AssumeSection 30.2 Nuclear Reactors1. If the average energy released in a fission event isenergy. Calculate the mass of 235 U consumedeach day.208 MeV, find the total number of fission events requiredto operate a 100-W lightbulb for 1.0 h.7. Suppose that the water exerts an average frictionaldrag of 1.0 10 5 N on a nuclear-powered ship.2. Find the energy released in the fission reactionThe atomic masses of the fission products are9897.912 0 u for Zr and 134.908 7 u for1354052 Te.How far can the ship travel per kilogram of fuel ifthe fuel consists of enriched uranium containing1.7% of the fissionable isotope 235 U and the ship’s208 MeV is released per fission event.)8. It has been estimated that the Earth contains1.0 10 9 tons of natural uranium that can be3. Find the energy released in the following fission reaction:mined economically. If all the world’s energyneeds (7.0 10 12 J/s) were supplied by 235 U10 n 23592 U : 8838Sr 13654 Xe 121 0 nfission, how long would this supply last? [Hint :See Appendix B for the percent abundance4. Strontium-90 is a particularly dangerous fissionproduct of 235 U because it is radioactive and it substitutesfor calcium in bones. What other direct fissionproducts would accompany it in the neutroninducedfission of 235 U? [Note : This reaction mayrelease two, three, or four free neutrons.]5. Assume that ordinary soil contains natural uranium inamounts of 1 part per million by mass. (a) How muchuranium is in the top 1.00 meter of soil on a 1-acre(43 560-ft 2 ) plot of ground, assuming the specificgravity of soil is 4.00? (b) How much of the isotope235 U, appropriate for nuclear reactor fuel, is in thissoil? [Hint : See Appendix B for the percent abundanceof235.]92 U6. A typical nuclear fission power plant producesabout 1.00 GW of electrical power. Assume thatthe plant has an overall efficiency of 40.0% and9.of23592U.]An all-electric home uses approximately2 000 kWh of electric energy per month.How much uranium-235 would be required to providethis house with its energy needs for 1 year? (Assume100% conversion efficiency and 208 MeV releasedper fission.)Section 30.3 Nuclear Fusion10. Find the energy released in the fusion reaction1121H H : He 11. When a star has exhausted its hydrogen fuel, it mayfuse other nuclear fuels. At temperatures above1.0 10 8 K, helium fusion can occur. Write theequations for the following processes: (a) Two alpha32