CHAPTER 13 1. What type of particle is emitted when a U-235 decays to Np-235? a. alpha particle b. beta particle c. neutron d. helium nuclei ANS: b 2. Stable nuclei (that is, nonradioactive nuclei) have mass numbers that are a. equal to the atomic number b. twice as large as the atomic number or even larger c. ten times the atomic number d. less than twice as large as the atomic number ANS: b 3. Which type of radiation has a charge of +1 and a mass of zero? a. positron b. beta c. alpha d. neutron ANS: a 4. Copper-64 in the form of copper acetate is used for a. in the diagnosis of brain tumors b. in the treatment of brain tumors c. in both diagnosis and treatment of brain tumors d. because Cu-64 has a long half-life ANS: a 5. Radon in the air arises from a. sun's ultraviolet radiation that enters earth's atmosphere b. radioactive decay of uranium in the soil c. increased use of microwave devices by humans d. radiation produced by worldwide use of electrical power lines ANS: b

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6. Who first discovered radioactivity? a. Ernest Rutherford b. Max Planck c. Marie Curie d. Henri Becquerel ANS: d 7. Which type of radiation is the most penetrating? a. gamma b. alpha c. beta d. all have about the same penetrating power ANS: a 8. Which is generally not associated with nuclear reactions? a. outer electrons b. atomic number c. atomic mass d. the nucleus ANS: a 9. The nuclear reaction that changes one element into another element is called a a. chemical reaction b. half-life c. transmutation d. decay series ANS: c 10. If the half-life of an element is 5 days and 100 milligrams of that element is initially

available, how many milligrams of the element are present after 25 days? a. 50 b. 100/25 c. 100/32 d. 100/64 ANS: c

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11. In the symbol 238U, the 238 is a. the mass number b. the atomic number c. the number of neutrons in the atom d. the number of protons in the atom ANS: a 12. The product of the beta ( −1

0β ) decay of thorium-234 is a. uranium-238 b. protactinium-234 c. uranium-234 d. uranium-235 ANS: b 13. The product of the alpha ( ) decay of uranium-238 is 2

4α a. Th-234 b. Th-230 c. U-234 d. U-242 ANS: a 14. What is the "stable" nucleus produced at the end of the decay steps in the uranium decay

series? a. thorium b. uranium c. radon d. lead ANS: d 15. Who was first to produce and describe an artificial nuclear reaction with the

bombardment of nitrogen with alpha particles? a. Geiger b. Wilson c. Rutherford d. Chadwick ANS: c

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16. What is the nucleus produced when beryllium-9, ( ), fuses with helium-4? 4

9Be a. oxygen-17 b. carbon-13 c. carbon-14 d. carbon-12 ANS: b 17. To make an alpha particle fuse with the nucleus of another atom, you need to a. aim carefully b. give the alpha particle a negative charge c. give the alpha particle a large amount of energy d. slow the particles down by cooling ANS: c 18. The first transuranium element to be discovered was a. Np b. Pu c. Hf d. Am ANS: a 19. What is the ultimate radioactive decay product of the uranium-238 series? a. radon gas b. lead c. uranium-235 d. alpha particles ANS: b 20. How many atoms of zinc-69 remain after a sample of 500,000 zinc-69 atoms decays for a

period of 165 minutes? The half-life time for zinc-69 is 55 minutes. a. 500,000 b. 62,500 c. 250,000 d. 125,000 ANS: b

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21. Which is larger in terms of radioactive disintegrations per second? a. one millicurie b. one microcurie c. one curie d. one picocurie ANS: c 22. The Food and Drug Administration, FDA, has approved the use of food irradiation to

prevent the growth of bacteria, molds, and yeasts in which of the following foods. a. uncooked beef b. uncooked pork c. uncooked poultry d. all of the above ANS: d 23. In 1934, when the Curies bombarded Al-27 with an alpha particle ( 2

4α ), the element produced was

a. silicon-29 and a neutron b. phosphorus-30 and a neutron c. silicon-29 and a positron d. phosphorus-30 and a positron ANS: b 24. When the nucleus of an atom of uranium-238 emits an alpha particle, the mass number

will a. decrease by 4 units b. decrease by 2 units c. increase by 4 units d. increase by 2 units ANS: a 25. Elements with atomic number greater than 83 beyond bismuth, Bi a. are beta emitters b. have short half-lives c. are unstable d. are synthetic ANS: c

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26. When a radioactive sample decays for 2 half-lives the amount remaining will be ____ of

the original. a. 1/4 b. 1/2 b. 1/8 d. unpredictable ANS: b 27. Gamma radiation from cobalt-60 or cesium-137 is used in a. agricultural research b. dating charcoal paintings c. food irradiation d. medical imaging ANS: c 28. Which is the opposite of an electron? a. α-particle b. positron c. neutron d. β-particle ANS: b 29. The quantity, 37,000 disintegration per second, is a. 1 curie b. 1 microcurie c. half-life of carbon-14 d. 1 bequerel ANS: b 30. In terms of nuclear stability, what atom is the most stable? a. Fe b. H c. U d. element 109 ANS: a

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31. Which statement is not true about fission? a. combination of atomic nuclei b. process requires initiation by a neutron c. a chain reaction d. products have smaller nuclei than reactants ANS: a 32. Which component of a nuclear reactor slows the speed of the neutron? a. shield b. heat-transfer fluid c. moderator d. uranium fuel ANS: c 33. Which country generates the least amount of electricity by nuclear fission? a. France b. Sweden c. United States d. Belgium ANS: c 34. Which is true about fusion? a. very high temperatures are required b. occurs in a plasma of charged particles c. produces fewer radioactive byproducts d. all statements are true ANS: d 35. Which atom can undergo fission by thermal neutrons? a. U-235 b. U-238 c. I-131 d. H-3 ANS: a

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3

6. The missing nucleus in the equation shown below is

---> + ? 90230 Th 2

4 He a. b. c. d. 92

234 U 88234 Ra 88

226 Ra 92226 U

ANS: c 37. Which is not true about plutonium-239? a. an unavoidable by-product in nuclear energy production b. short half-life c. fissionable d. used in nuclear war heads ANS: b 38. Tritium, H-3, and hydrogen, H-1, are a. fission reactants b. fission products c. fusion reactants d. fusion products ANS: c 39. The splitting of a nucleus by a slow moving neutron is called a. fission b. fusion c. fragmentation d. annihilation ANS: a 40. Binding energy of a nucleus is a. the energy emitted when separate neutrons, protons, and electrons combine to form

an atom b. the energy required to dissociate an atom into separate neutrons, protons, and

neutrons c. equivalent to a quantity of mass expressed by Einstein's equation, E = mc2 d. all of the preceding answers ANS: b

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41. A major, unsolved problem with nuclear energy is a. cost b. engineering problems with design reactors c. acquiring land on which to build nuclear reactors d. what to do with nuclear wastes with long half-lives ANS: d 42. The fusion of nuclei requires a. a critical mass b. plasma at extremely high temperatures c. heavy nuclei d. slow moving (thermal) neutrons ANS: b 43. What produces the tremendous energy of a nuclear fission reaction? a. some mass being changed into energy b. the splitting of the nucleus c. the extra neutrons produced d. disintegration of the containment building ANS: a 44. Chernobyl is the site of a 1986 nuclear reactor accident that a. killed 4300 workers who cleaned up the site b. occurred near Kiev, Ukraine c. occurred when the graphite (carbon) core caught fire d. all of these ANS: d 45. The EPA warns that 8 million homes in the U.S. may have radon contamination higher

than the "action level". Why is radon a concern? a. it is linked to breast cancer b. it is linked to lung cancer c. it is linked to prostrate cancer d. all of these ANS: b

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46. Which type of radiation has no charge or mass? a. positron b. beta c. alpha d. gamma ANS: d 47. What type of particle is emitted when a Po-210 decays to Pb-206? a. alpha particle b. beta particle c. neutron d. helium nuclei ANS: d 48. Which type of radiation can penetrate a thin piece of lead? a. gamma b. alpha c. beta d. all the above ANS: a 49. If the half-life of an element is 12 years. How much of a 5.00 g sample remains after 36

years? a. 2.50 b. 1.25 c. 0.625 d. 0.313 ANS: c 50. The product of the gamma decay of lead-210 is a. bismuth-210 b. lead-210 c. bismuth 209 d. lead-209 ANS: b

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51. Is it possible to determine the age of an artifact that is estimated to be 100,000 years old by radiocarbon dating?

a. Yes, because the half-life of carbon is 5730 years b. No, because the half-life of carbon is only 12 years c. Yes, because the amount of carbon remaining is very high d. No, because the amount of carbon remaining is very low ANS: d 52. Identify the atoms that could be used in nuclear fission and fusion, respectively? a. C-14 and H-3 b. Rn-222 and H-3 c. Rn-222 and U-238 d. Fe-56 and H-1 ANS: b 53. What is the process in which neutrons from one fission reaction can cause multiple

fission reactions in nearby nuclei? a. critical mass b. radiocarbon dating c. chain reaction d. binding energy ANS: c 54. Identify the high-level radioactive waste? a. weapons industry waste b. laboratory clothing waste c. medical waste d. smoke detector waste ANS: a 5

5. The missing nucleus in the equation shown below is

Pa → e + ? 23491

01−

a. b. c. d. 92

234 U 88234 Ra 88

226 Ra 92226 U

ANS: a

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