1. Uranium-235 decays via a sequence of seven alpha decays and four beta decays to produce a stable nuclide. Which of the following is the nuclide that is produced?
   1. tungsten-207
   2. lead-207
   3. actinium-235
   4. proactinium-219
   5. uranium-238

2. The half-life of tritium is 12.3 years. If 48.0 mg of tritium is released from a nuclear power plant during the course of an accident, calculate the mass (in mg) of the nuclide that will remain after 5.0 years.

3. Nuclides that have neutron-to-proton ratios that are too HIGH (compared with stable nuclides) are expected to undergo:
   1. alpha decay.
   2. beta decay.
   3. positron decay.
   4. electron capture.
   5. none of the above.

4. Radon-222 is a potentially serious problem in many homes. From which of the following naturally-occurring nuclides is radon-222 produced?
   1. carbon-12
   2. potassium-40
   3. iron-56
   4. thorium-232
   5. uranium-238

5. Consider the following types of medical procedures,

   i. PET (Positron Emission Tomography) scan
   ii. CAT (Computerized Axial Tomography) scan
   iii. MRI (Magnetic Resonance Imaging) scan
   iv. Iodine-131 treatment of hyperthyroidism

   Which of these procedures involves X-rays?

   1. i and iii
   2. ii and iv
   3. iii and iv
   4. i only
   5. ii only

6. Isotones are nuclides that have the same number of neutrons. Which of the following pairs of nuclides are isotones?
   1. oxygen-15 and nitrogen-15
   2. oxygen-16 and oxygen-17
   3. neon-20 and sodium-23
   4. magnesium-25 and aluminum-26
   5. None of these.

7. Some lantern mantles are manufactured using thorium-232 to increase the durability of the mantle. Thorium-232 undergoes alpha decay with a half-life of 1.4 x 10¹⁰ years. Which of the following is the product nuclide of the decay of thorium-232?
   1. radium-228
   2. actinium-232
   3. proactinium-232
   4. uranium-236
   5. None of these.

8. Nuclear fission of uranium-235 nuclei produces ON AVERAGE:
   1. 1 neutron.
   2. 2 neutrons.
   3. 3 neutrons.
   4. 4 neutrons.
   5. 5 neutrons.

9. Uranium-234 radioactively decays by alpha-particle emission. The neutron-to-proton ratio of the product nuclide is:
   1. smaller than that for uranium-234.
   2. greater than that for uranium-234.
   3. the same as that for uranium-234.
   4. equal to 1.0.
   5. It is impossible to tell.

10. Which of the following can be detected by a Geiger counter?
    1. alpha particles
    2. beta particles
    3. gamma rays
    4. All of these.
    5. None of these.

11. Which of the following statements about radon-222 is TRUE?
    1. The radioactive decay products of radon-222 are solids.
    2. Radon-222 is produced via a series of radioactive decay steps from naturally-occurring plutonium.
    3. Radon-222 is a green gas that smells like lemons.
    4. The density of radon-222 is less than the density of air.
    5. None of these are TRUE.

12. Strontium-90 is one of the harmful nuclides resulting from nuclear fission explosions. Strontium-90 decays by beta particle emission with a half-life of 28.0 years. How long (in years) would it take for 99.0% of a sample of strontium-90 released in an atmospheric test of an atomic bomb to decay?

13. In which of the following medical diagnostic procedures is a radioactive substance introduced into the patient's body?
    1. MRI scan
    2. PET scan
    3. CAT scan
    4. DOG scan
    5. FISH scan

14. Fluorine-18 radioactively decays by the emission of a positron. Which of the following is the product nuclide of this decay?
    1. nitrogen-14
    2. neon-18
    3. oxygen-18
    4. fluorine-17
    5. fluorine-18

15. The chemistry of atoms, molecules and ions is determined primarily by the number and arrangement of which of the following?
    1. positrons
    2. electrons
    3. neutrons
    4. quarks
    5. alpha particles

16. Uranium-235 decays in a series of steps to produce the stable nuclide, lead-207. Which of the following series of decays would produce lead-207 from uranium-235?
    1. 6 alpha + 2 beta
    2. 3 alpha + 3 positron
    3. 7 alpha + 4 beta
    4. 5 alpha + 6 beta
    5. 7 alpha

17. Which of the following statements about food irradiation is TRUE?
    1. The irradiated food is radioactive.
    2. Irradiation of food produces chemical degradation products similar to those produced from cooking food using heat.
    3. Food irradiation employs positrons.
    4. The radioactive nuclide that is used in food irradiation is thorium-230.
    5. In the U.S., there are no foods which have been approved by the FDA for treatment by irradiation.

18. Which of the following characteristics of particles produced by radioactive decay are important for assessing the potential for biological damage to living systems?
    1. mass
    2. charge
    3. penetrating ability
    4. kinetic energy
    5. All of these.

19. The first orange "Fiestaware" dishes contained salts of uranium as pigments. If one of these "Fiestaware" dishes initially contained 0.50 g of uranium-238, calculate how long it would take (in years) for the uranium-238 to decay to 0.25 g. For uranium-238, t_1/2 = 4.5 x 10⁹ years.

20. Which of the following nuclides is used medicinally to treat hyperthyroidism?
    1. uranium-238
    2. americium-241
    3. carbon-14
    4. iodine-131
    5. thorium-232

21. In lecture, the use of radiation to treat food and other consumer products was discussed. Which of the following radioactive nuclides is currently being used for food irradiation?
    1. uranium-238
    2. radon-222
    3. carbon-14
    4. cobalt-60
    5. americium-241

22. Carbon-14 radioactively decays via the emission of a beta particle. Which of the following is the product nuclide of this decay?
    1. beryllium-10
    2. boron-14
    3. carbon-13
    4. carbon-14
    5. nitrogen-14

23. In fluorine-18, the neutron-to-proton ratio is too low and this nuclide undergoes radioactive decay. Which of the following decay processes would be expected to produce a nuclide with a neutron-to-proton ratio GREATER THAN that for fluorine-18?
    1. alpha decay
    2. beta decay
    3. gamma decay (only)
    4. positron decay
    5. None of these.

24. Thorium-232 decays in a series of steps to produce the unstable nuclide, radon-220. Which of the following series of decays would produce radon-220 from thorium-232?
    1. 3 alpha + 2 beta
    2. 4 alpha + 2 beta
    3. 5 alpha + 2 beta
    4. 2 alpha + 3 beta
    5. 1 alpha + 2 beta

25. The radioactive nuclide, radon-222, is a problem in the basements of many homes. Calculate how long (in days) it would take for a 3.65 g sample of radon-222 to decay to 1.34 g? Radon-222 decays by a first-order process with a half-life of 3.82 days.

26. An archeologist unearths a bone sample and wants to know the age of the bone. Her chemist friend determines that 45.3% of the initial amount of carbon-14 is present in the bone sample. If the half-life of carbon-14 is 5730 years, calculate the age (in years) of the bone.

27. The following are produced by radioactive decay processes. Which one has the GREATEST mass?
    1. alpha particle
    2. beta particle
    3. gamma ray
    4. neutron
    5. positron

28. In lecture, you observed an instrument gauge from a World War II vintage aircraft which had been painted with a radioactive element. Which of the following elements was used in the paint?
    1. uranium
    2. plutonium
    3. radium
    4. polonium
    5. neptunium

29. Naturally occurring uranium-238 decays in a series of steps to produce the stable nuclide, lead-206 . Which of the following series of decays would produce lead-206 from uranium-238?
    1. 3 alpha + 4 beta
    2. 4 alpha + 3 beta
    3. 5 alpha + 2 beta
    4. 2 alpha + 5 beta
    5. 8 alpha + 6 beta

30. One of the factors that determines how effective a particular type of radiation will be in causing biological damage is the mass of the particle. Which of the following has the GREATEST mass?
    1. alpha particle
    2. beta particle
    3. positron
    4. gamma ray
    5. neutron

31. The function of the MODERATOR in a nuclear power plant is to:
    1. carry the heat produced from the fission reactions to an external turbine.
    2. absorb neutrons and thereby control the fission reactions.
    3. protect the workers and the environment from radiation.
    4. slow down the neutrons produced from the fission reactions so that they can be absorbed by more fuel.
    5. None of the above responses is correct.

32. In lecture, you observed an "EXIT" sign that contained a radioactive nuclide. Which of the following nuclides was used in the "EXIT" sign?
    1. uranium-238
    2. potassium-40
    3. hydrogen-3 (tritium)
    4. phosphorus-32
    5. carbon-14

33. The neutron often plays a key role in radioactive decay because it is:
    1. attracted by the strong force.
    2. capable of converting to a proton and an electron.
    3. unaffected by the coulombic force.
    4. able to act as a nuclear "glue".
    5. All of these statements are true.

34. When polonium-216 decays by the emission of one alpha particle and two beta particles, the product is the isotope:
    1. polonium-210
    2. polonium-212
    3. polonium-214
    4. polonium-218
    5. polonium-220

35. The nuclide sulfur-35 is neutron-rich, therefore, it is likely to undergo radioactive decay by:
    1. beta emission.
    2. electron capture.
    3. positron emission.
    4. neutron emission.
    5. alpha emission.

36. Based on the number of protons only, which of the following unknown nuclides is MOST likely to undergo radioactive decay?
    1. silicon-30
    2. germanium-72
    3. barium-130
    4. radon-216
    5. All of the above.

37. In a graph of binding energy per nucleon vs. atomic mass, Fe, has the highest binding energy per nucleon of all nuclei. This means that:
    1. Fe is more stable than any other nuclide.
    2. Nuclei lighter than Fe become more stable by fission processes.
    3. Fe decays by positron emission.
    4. Nuclei heavier than Fe become more stable by fusion processes.
    5. All of these statements are true.

38. The mass of one atom of chromium-52 is 51.9405 amu. The binding energy per nucleon for the chromium-52 nucleus is:
    1. 7.1 MeV
    2. 7.9 MeV
    3. 8.8 MeV
    4. 10.1 MeV
    5. 12.4 MeV

39. Which of the following processes is an example of nuclear fusion?
    1. bismuth-209 + helium-4 --> astatine-211 + 2 neutrons
    2. hydrogen-2 + hydrogen-2 --> hydrogen-3 + hydrogen-1
    3. plutonium-239 + neutron --> americium-240 + beta particle
    4. uranium-239 --> neptunium-239 + beta particle
    5. None of the reactions involve fusion.

40. Uranium-238 has a binding energy of approximately 7.5 MeV per nucleon. What spontaneous radioactive decay process would be predicted to occur as a result of bombarding uranium-238 with neutrons?
    1. beta particle emission
    2. a fission reaction
    3. electron capture
    4. a fusion reaction
    5. positron emission

41. Ionizing radiation is many times more dangerous to biological systems than non-ionizing radiation. The radiation that causes the most damage, if ingested, is:
    1. alpha particles.
    2. beta particles.
    3. gamma rays.
    4. protons.
    5. ultraviolet.

42. Orange-colored Fiesta tableware causes a Geiger counter to emit a rapid clicking sound. The BEST explanation of this phenomenon is that the pottery:
    1. has a lead glaze.
    2. undergoes fusion.
    3. is made with uranium ores.
    4. emits neutrons.
    5. is painted with radium-based paints.

43. Isotopes with neutron to proton ratios that are too low would be expected to undergo radioactive decay by which one of the following processes? That is, which of the following processes would result in an increase in the neutron to proton ratio?
    1. neutron emission
    2. beta particle emission
    3. alpha particle emission
    4. gamma ray emission
    5. positron emission

44. The presence of radon-222 in homes poses a serious health risk. Radon-222 decays by alpha particle emission with a half-life of 3.8 days. Which of the following is the product nuclide from this decay?
    1. astatine-221
    2. francium-222
    3. astatine-222
    4. radon-221
    5. polonium-218

45. Naturally occurring uranium-238 decays in a series of steps to produce the stable nuclide, lead-206. The product nuclide that results after the seventh step in this decay series is polonium-218. Which of the following series of decays would produce polonium-218 from uranium-238?
    1. 3 alpha + 4 beta
    2. 4 alpha + 3 beta
    3. 5 alpha + 2 beta
    4. 2 alpha + 5 beta
    5. 1 alpha + 6 beta

46. Which of the following types of radiation generally has the greatest potential for biological damage?
    1. alpha particles
    2. beta particles
    3. gamma rays
    4. positrons
    5. neutrons

47. Positron Emission Tomography (PET) is a medical diagnostic technique that is based on which one of the following processes?
    1. neutron bombardment
    2. fission
    3. annhilation
    4. fusion
    5. electron scattering

48. An isotope of an element decays by emitting an alpha particle and forming lead-208. The original element was:
    1. Bi
    2. Hg
    3. Po
    4. Rn
    5. Tl

49. The only stable isotope of fluorine is fluorine-19. What type of radioactivity would you expect from the isotope fluorine-18, which has one less neutron?
    1. protons
    2. neutrons
    3. beta particles
    4. positrons
    5. alpha particles

50. The isotope with the greatest nuclear binding energy per nucleon is:
    1. hydrogen-2
    2. helium-4
    3. carbon-14
    4. iron-56
    5. uranium-238

51. The carbon-14 activity of some ancient Peruvian corn was found to be 10 disintegrations/minute/gram. If present-day plant life shows 15 disintegrations/minute/gram, how old is the Peruvian corn? The half-life of carbon-14 is 5,730 years.
    1. 1,455 years
    2. 1,910 years
    3. 3,350 years
    4. 3,820 years
    5. 9,080 years

52. Which type of nuclear process requires a temperature of over a million degrees?
    1. beta particle production
    2. fission reaction
    3. alpha particle emission
    4. fusion reaction
    5. positron production

53. In passing through matter, alpha particles lose energy and damage tissues by producing:
    1. neutrons.
    2. gamma rays.
    3. radiation.
    4. beta particles.
    5. ions.

54. It is well-known that uranium isotopes can undergo fission reactions and that hydrogen isotopes can undergo fusion reactions. These reactions are examples of a drive toward:
    1. equilibrium.
    2. thermodynamic stability.
    3. negative S.
    4. kinetic stability.
    5. positive G.

55. Which of the following balanced equations indicates a FUSION reaction?
    1. bismuth-209 + helium-4 --> astatine-211 + 2 neutrons
    2. helium-2 + hydrogen-2 --> hydrogen-3 + hydrogen-1
    3. plutonium-239 + neutron --> americium-240 + beta particle
    4. uranium-239 --> neptunium-239 + beta particle
    5. beryllium-7 + electron --> lithium-7

56. Which statement is FALSE?
    1. The larger the binding energy per nucleon, the more stable the nucleus.
    2. The alpha particle has a charge of 2+.
    3. The mass of a nucleus is always less than the original mass of its constituent protons and neutrons.
    4. Alpha particle production is the only route by which unstable nuclei can spontaneously decay.
    5. Alpha particles are more massive than beta particles.

57. Iron-49 decays by positron emission with a half-life of 0.08 seconds. What nuclide is produced in this decay process?
    1. manganese-49
    2. cobalt-49
    3. chromium-45
    4. iron-48
    5. None of these.

58. The following are produced in radioactive decay processes. Which one has neither mass nor charge?
    1. alpha particles
    2. beta particles
    3. gamma rays
    4. positrons
    5. neutrons

59. The function of the CONTROL RODS in a nuclear power plant is to:
    1. slow the neutrons down so that they can cause fission.
    2. absorb the heat produced so that it can be carried to an external turbine.
    3. absorb neutrons to control the amount of fission that is occuring.
    4. provide the fuel needed for fission to occur.
    5. None of the above.

60. Smoke detectors contain a small amount of americium-241. What is the final product nuclide if americium-241 radioactively decays by a total of eight alpha decays and four beta decays?
    1. rhenium-209
    2. gold-209
    3. bismuth-209
    4. plutonium-237
    5. americium-225

61. Which one of the following types of particles is the MOST highly penetrating to biological tissues?
    1. alpha particles
    2. beta particles
    3. positrons
    4. neutrons
    5. electrons

62. In lecture, you observed a radioactive plate that contained uranium oxide as a pigment (i.e., "Fiestaware"). What color was the plate?
    1. yellow
    2. purple
    3. white
    4. orange
    5. green

63. An ancient wood sculpture was determined to be 2380 years old. Calculate the percentage of the carbon-14 originally present in the wood that remains today. For carbon-14: t_1/2 = 5730 years.

64. Americium-241 is the radioactive isotope that is used in smoke detectors. Americium-241 undergoes alpha decay with a half-life of 458 years. What is the product nuclide that is produced when americium-241 radioactively decays?
    1. neptunium-237
    2. curium-241
    3. plutonium-241
    4. americium-240
    5. plutonium-240

65. Positron emission tomography (PET) scans are used medicinally to diagnose certain biological disorders. The most common radioactive isotope used in this procedure is fluorine-18, which is a positron emitter. In a PET scan, which one of the following species is actually measured in order to create a three-dimensional image of the afflicted organ?
    1. alpha particles
    2. beta particles
    3. gamma rays
    4. positrons
    5. neutrons

66. In lecture, you observed a desiccator that was used for many years to store radioactive radium compounds. What color was the desiccator?
    1. yellow
    2. orange
    3. purple
    4. green
    5. black

67. The radioactive nuclide, iodine-131, is used medicinally as a radiotracer for the diagnosis and treatment of illnesses associated with the thyroid gland. If the rate constant for decay of iodine-131 is 9.9 x 10^-7 s^-1, calculate the half-life (in s) of iodine-131.

68. Calculate the binding energy per nucleon in millions of electron volts (MeV) for nitrogen-15. The atomic mass of nitrogen-15 is 15.00011 amu.

69. What is the final, stable nuclide, X, if radon-222 decays by the emission of four alpha particles and four beta particles?
    1. tungsten-206
    2. tungsten-214
    3. platinum-202
    4. platinum-210
    5. lead-206

70. An archeologist unearths a bone sample and wants to know the age of the bone. Her chemist friend determines that 41.7% of the initial amount of carbon-14 in the bone sample has decayed. If the half-life of carbon-14 is 5730 years, the age of the bone is:
    1. 4460 years
    2. 5730 years
    3. 7230 years
    4. 10200 years
    5. 11460 years

71. Which of the following characteristics is/are important considerations for radiotracers that will be used for diagnosing illness in the body?
    1. The radiotracer should have a short half-life.
    2. The radiotracer should localize in a certain part of the body.
    3. The radiotracer should produce radiation that can be detected externally.
    4. (a) and (b).
    5. (a), (b) and (c).

72. When a nuclide is assembled from its constituent protons, neutrons, and electrons, there is about a 1% decrease in mass. When a chemical compound is similarly made from its constituent elements there is no discernible change in mass. The best reason for this difference is that:
    1. chemical reactions are intrinsically different from nuclear reactions.
    2. the formation of a nuclide from its constituents is always exothermic whereas the formation of a compound from the elements can be either exothermic or endothermic.
    3. Einstein's equation, E = mc², applies to nuclei but not to molecules.
    4. chemical reactions release far less energy than nuclear reactions and so the mass change is too small to observe.
    5. mass is conserved in chemical reactions but is not conserved in nuclear reactions.

73. The mass of chlorine-37 is 36.96590 amu. The binding energy per nucleon of chlorine-37 is:
    1. -1.41 x 10^-12 J/nucleon
    2. 1.29 x 10^-12 J/nucleon
    3. 1.37 x 10^-12 J/nucleon
    4. 5.08 x 10^-11 J/nucleon
    5. 5.08 x 10^-8 J/nucleon

74. The only stable nuclide with A = 35 is chlorine-35. Which of the following equations correctly describe the process by which phosphorus-35 decays to chlorine-35?
    1. phosphorus-35 -> chlorine-35 + beta particle
    2. phosphorus-35 -> sulfur-35 + beta particle
       sulfur-35 -> chlorine-35 + beta particle
    3. phosphorus-35 -> silicon-35 + beta particle
       silicon-35 -> chlorine-35 + beta particle
    4. phosphorus-35 -> chlorine-35 + positron
    5. phosphorus-35 + e- -> sulfur-35
       sulfur-35 + e- -> chlorine-35

75. A freshly prepared sample of yttrium-90 undergoes 7.6 x 10⁵ disintegrations per minute (dpm) at a certain time. Exactly 14 days later, the same sample undergoes 1.6 x 10⁴ dpm. The half-life of yttrium-90 is:
    1. 0.20 day
    2. 2.5 day
    3. 2.7 day
    4. 3.8 day
    5. 14 day

76. What is the product nuclide of the decay of thorium-232? Thorium-232 has a half-life of 1.4 x 10¹⁰ years and radioactively decays by alpha emission.
    1. radon-230
    2. radium-228
    3. actinium-232
    4. proactinium-232
    5. uranium-235

77. Calculate the binding energy per nucleon of boron-11 if the atomic mass of boron-11 is 11.00931 amu.
    1. 3.54 MeV
    2. 5.67 MeV
    3. 6.94 MeV
    4. 7.82 MeV
    5. 8.23 MeV

78. An archeologist unearths a bone sample and wants to know the age of the bone. Her chemist friend determines that 35.6% of the initial amount of carbon-14 is present in the bone sample. If the half-life of carbon-14 is 5730 years, the age of the bone is:
    1. 3640 years
    2. 5730 years
    3. 8540 years
    4. 10200 years
    5. 11460 years

79. Consider the following types of medical procedures that are used for diagnosing various illnesses:
    1. PET (Positron Emission Tomography) scans
    2. CAT (Computerized Axial Tomography) scans
    3. MRI (Magnetic Resonance Imaging) scans
    4. Tc bone scans
    5. Tl cardiac scans

    Which of these diagnostic procedures involves radioactive decay of an unstable nuclide as the primary means for creating an image of the area of the body being studied?

    1. 1, 2 and 3
    2. 2 and 3
    3. 3, 4 and 5
    4. 1, 4 and 5
    5. 2, 4 and 5

80. Four types of radiation arranged in order from lowest to highest health hazard is:
    1. gamma rays < alpha particles < beta particles < neutrons
    2. alpha particles < gamma rays < neutrons < beta particles
    3. beta particles < alpha particles < gamma rays < neutrons
    4. neutrons < alpha particles < gamma rays < beta particles
    5. gamma rays < beta particles < neutrons < alpha particles

81. Write a chemical equation for each of the following radioactive decay processes:
    1. phosphorus-32 decays by beta-particle emission.

    2. lithium-8 decays by beta-particle emission followed by alpha-particle emission.

    3. potassium-40 decays by electron capture.

    4. nitrogen-13 decays by positron emission.

    5. thorium-232 decays by alpha-particle emission.

82. Calculate the binding energy per nucleon in millions of electron volts for magnesium-27. The atomic mass of magnesium-27 is 26.9843 amu.

83. Consider the following information:
    1. The layer of dead skin on our bodies is sufficient to protect us from most alpha-particle radiation.

    2. Plutonium is an alpha-particle producer.

    3. The chemistry of Pu⁴⁺ is similar to that of Fe³⁺.

    4. Pu⁴⁺ + 4 e^- --> Pu, E^o = -1.28 V

    Using this information, explain why plutonium is one of the most toxic substances known.

84. Suppose that an archeologist has unearthed a human bone. She asks her chemist friend to determine the percentage of carbon-14 present in the bone. The chemist determines that the bone sample contains 67.3% of the carbon-14 present in living tissue. If the half-life of carbon-14 is 5730 years, calculate the age (in years) of the bone.

85. Carbon-14 undergoes radioactive decay because it has a neutron-to-proton (n/p) ratio that is too large. The GREATEST reduction in the neutron-to-proton ratio of the product nuclide can be achieved by the emission of a(n):
    1. alpha particle.
    2. beta particle.
    3. positron.
    4. neutron.
    5. gamma ray.

86. Thallium-201 is used in medicine to create images of the heart. A thallium-201 nucleus contains:
    1. 0 neutrons.
    2. 81 neutrons.
    3. 120 neutrons.
    4. 201 neutrons.
    5. None of these.

87. Uranium-235 undergoes radioactive decay in a series of steps to produce the stable nuclide, lead-207. If the radioactive decay of uranium-235 involves the emissions (in order): alpha, beta, alpha, beta, alpha, alpha, alpha, alpha, beta, alpha, beta, which of the following nuclides are NOT produced in the decay series?
    1. radon-219
    2. thallium-207
    3. radium-223
    4. proactinium-233
    5. polonium-215

88. Scientists have recently shown that a sample of cocaine can be traced to its country of origin by measuring the ratio of carbon-13 to nitrogen-15 (both naturally occurring, stable nuclides) in the cocaine sample. Carbon-14 and nitrogen-16, however, do not occur naturally and both of these nuclides undergo radioactive decay by the same process. Which of the following is the most likely type of radioactive decay for carbon-14 and nitrogen-16?
    1. alpha decay
    2. beta decay
    3. positron decay
    4. spontaneous fission
    5. electron capture

89. Uranium-235 is one of the most common fuels used in nuclear power plants. However, uranium-238 cannot be used as a fuel in a nuclear power plant. Which of the following statements best explains why uranium-238 cannot be used as a fuel?
    1. There is not enough uranium-238 in naturally occurring uranium to use it as a fuel.
    2. It is not possible to construct fuel rods which contain uranium-238.
    3. Uranium-238 does not undergo radioactive decay.
    4. Uranium-238 is not a naturally occurring isotope of uranium.
    5. Uranium-238 does not undergo fission easily enough to be used as a fuel.

90. Fluorine-18 is one of the radioactive nuclides utilized in Positron Emission Tomography (PET) scans. Fluorine-18 can be synthesized by bombarding oxygen-18 nuclei with hydrogen-1 nuclei,
    oxygen-18 + hydrogen-1 --> fluorine-18 + X

    What is the identity of the other product, X, in this reaction?

    1. alpha particle
    2. beta particle
    3. positron
    4. neutron
    5. gamma ray

Answers

1. B
2. 36.2
3. B
4. E
5. E
6. D
7. A
8. C
9. B
10. D
11. A
12. 1.9 x 10²
13. B
14. C
15. B
16. C
17. B
18. E
19. 4.5 x 10⁹
20. D
21. D
22. E
23. D
24. A
25. 5.5
26. 6.5 x 10³
27. A
28. C
29. E
30. A
31. D
32. C
33. E
34. B
35. A
36. D
37. A
38. C
39. B
40. B
41. A
42. C
43. E
44. E
45. C
46. E
47. C
48. C
49. D
50. D
51. C
52. D
53. E
54. B
55. B
56. D
57. A
58. C
59. C
60. C
61. D
62. D
63. 75
64. A
65. C
66. C
67. 7 x 10⁵
68. 7.7
69. E
70. A
71. E
72. D
73. C
74. B
75. B
76. B
77. C
78. C
79. D
80. A
81. 1. phosphorus-32 -> beta particle + sulfur-32
    2. 1. lithium-8 -> beta particle + beryllium-8
       2. beryllium-8 -> alpha particle + alpha particle
    3. potassium-40 + electron -> argon-40
    4. nitrogen-13 -> positron + carbon-13
    5. thorium-232 -> alpha particle + radium-228

82. 8.29

83. The first two facts indicate that Pu is not a significant threat outside of the body. However, if Pu gets inside of the body (ingested or inhaled), the electrochemical data indicate that it can be easily oxidized to Pu⁴⁺:

    Pu -> Pu⁴⁺ + 4e^-, E^o = 1.28 V

    The large positive potential indicates that oxidation of Pu is quite favorable. Now, because the chemistry of Pu⁴⁺ is similar to Fe³⁺, Pu⁴⁺ will tend to concentrate in tissues where Fe³⁺ is found. For example, Pu⁴⁺ could concentrate in bone marrow where red blood cells are produced (recall, hemoglobin has a central Fe³⁺ ion). Once concentrated there, the alpha particles produced from its decay can do significant damage to the tissue.

84. 3270
85. B
86. C
87. D
88. B
89. E
90. D