A an alpha particle B a beta particleC a deuteron D a triton

1. Given the nuclear equation:147N + X ® 168O + 21HWhat is particle X?

A alpha particle B beta particleC gamma ray D neutron

2. Which type of radioactive emission has a positive chargeand weak penetrating power?

A alpha particles B beta particlesC gamma rays D neutrons

3. Which radioactive emanations have a charge of 2+?

A decrease by 2 B increase by 2C decrease by 4 D increase by 4

4. When an alpha particle is emitted by an atom, the atomicnumber of the atom will

A 23994Pu ® 23592U + 42HeB 2713Al + 42He ® 3015P + 10nC 23892U + 10n ® 23994Pu + 2 0-1eD 23994Pu + 10n ® 14756Ba + 9038Sr + 310n

5. Which reaction is an example of natural transmutation?

A an alpha particle B a beta particleC a gamma ray D a neutron

6. Given the nuclear equation:

232 90Th ® 228 88Ra + X

The letter X in the equation represents

A an alpha particle B a beta particleC a positron D a gamma ray

7. An unstable nucleus loses the most mass if the nucleusemits

A proton ® electron ® alpha particleB proton ®alpha particle ® electronC electron ® proton ® alpha particleD alpha particle ® electron ® proton

8. Which list of particles is in order of increasing mass?

A alpha B betaC positron D proton

9. Which type of radiation is identical in mass and chargeto a helium nucleus?

A alpha B betaC neutron D positron

10. Which of these particles has the greatest mass?

A a neutron B a protonC an alpha particle D a beta particle

11. In the reaction 23993Np ®23994Pu + X, what does X represent?

A alpha particle B beta particleC proton D neutron

12. Which of the following particles has the least mass?

A a neutron B a protonC an alpha particle D a beta particle

13. An electron has a charge identical to that of

14. A radioactive source emits radiation which is deflectedas shown in the diagram below.

A 0–1e B 42He C 11H D 10n

This radiation could be

A mass, onlyB charge, onlyC both mass and chargeD neither mass nor charge

15. Alpha particles and beta particles differ in

A 87 37 Rb ® 0 –1 e + 87 38 SrB 277 92 U ® 223 90 Th + 4 2 HeC 2713Al + 42He ® 3015P + 10nD 11 6 C ® 0 +1 e + 11 5 B

16. Which equation represents positron decay?

17. Base your answer to the following question on Giventhe nuclear reaction:

A fissionB fusionC artificial transmutationD natural transmutation

This reaction is an example of

A potassium-37 B radium-226C nitrogen-16 D thorium-232

18. Positrons are spontaneously emitted from the nuclei of

A a transmutation occurred without particle emissionB a transmutation occurred with particle

emissionC nitrogen-14 has an unstable nucleusD carbon-14 has a stable nucleus

19. A carbon-14 atom spontaneously decayed to form anitrogen-14 atom. This change took place because

A a lithium ion B an alpha particleC an aluminum ion D a beta particle

20. Which particle has a negative charge?

A alpha B betaC gamma D neutron

21. Which kind of nuclear radiation has high energy and nomass?

A gamma B neutronC alpha D beta

22. Which type of radiation has neither mass nor charge?

A It has a mass of 1 and a charge of 1.B It has a mass of 0 and a charge of –1.C It has a mass of 0 and a charge of 0.D It has a mass of 4 and a charge of +2.

23. Which statement best describes gamma radiation?

24. A mixture of emanations from radioactive atoms ispassed through electrically charged plates, as shown inthe diagram below.

A alpha, beta, and gammaB beta, gamma, and alphaC gamma, alpha, and betaD gamma, beta, and alpha

The nuclear emanations 1, 2, and 3 are called,respectively,

A mass but no chargeB charge but no massC neither mass nor chargeD both mass and charge

25. Gamma rays are emanations that have

A decreases B increasesC remains the same

26. As a sample of the radioactive isotope 131I decays, itshalf-life

27. The graph below represents the decay of a radioactiveisotope.

A 32P B 131I C 198Au D 222Rn

Based on Reference Table H, which radioisotope is bestrepresented by the graph?

A decreases B increasesC remains the same

28. As a sample of a radioactive element decays, itshalf-life

A 1.3 × 109 y B 2.6 × 109 yC 3.9 × 109 y D 1.2 × l09 y

29. An original sample of K-40 has a mass of 25.00 grams.After 3.9 × 109 years, 3.125 grams of the originalsample remains unchanged. What is the half-life ofK-40?

A 8.0 B 16 C 20. D 24

30. In how many days will a 12-gram sample of 13153Idecay, leaving a total of 1.5 grams of the originalisotope?

A 8 × 12.4 hours B 2 × 12.4 hoursC 3 × 12.4 hours D 4 × 12.4 hours

31. Exactly how much time must elapse before 16 grams ofpotassium-42 decays, leaving 2 grams of the originalisotope?

A 10 B 20 C 30 D 40

32. If 80 milligrams of a radioactive element decays to 10milligrams in 30 minutes, what is the element's half-lifein minutes?

A 11.5 min B 23.0 minC 34.5 min D 46.0 min

33. If of an original sample of krypton-74 remainsunchanged after 34.5 minutes, what is the half-life ofkrypton-74?

A cesium-137 B francium-220C phosphorus-32 D strontium-90

34. Which nuclide has a half-life that is less than oneminute?

A 1.91 days and alpha decayB 1.91 days and beta decayC 3.82 days and alpha decayD 3.82 days and beta decay

35. What is the half-life and decay mode of Rn-222?

A 12.5 days B 25.0 daysC 37.5 days D 75.0 days

36. A 40.0 milligram sample of 33P decays to 10.0milligrams in 50.0 days. What is the half-life of 33P?

A 12

B 14

C 18

D 1 16

37. Approximately what fraction of an original Co–60sample remains after 21 years?

A Fr-220 B K-42C N-16 D P-32

38. Which radioisotope undergoes beta decay and has ahalf-life of less than 1 minute?

A 1995 B 2000 C 2006 D 2011

39. If 8.0 grams of a sample of 60Co existed in 1990, inwhich year will the remaining amount of 60Co in thesample be 0.50 gram?

A 8 B 16 C 3 D 4

40. What is the number of half-life periods required for asample of a radioactive material to decay toone-sixteenth its original mass?

A 1.91 days B 3.82 daysC 7.64 days D 11.5 days

41. How many days are required for 200. grams ofradon-222 to decay to 50.0 grams?

A 12

B 14

C 18

D 1 16

42. The half-life of 146C is 5,730 years. What fraction of a 1gram sample of 146C would remain after 17,190 years?

43. Base your answer to the following question on on thegraph below. The graph represents the decay ofradioactive material X into a stable decay product.

A B

C D

Which graph best represents the relative percentages ofradioactive material X and its stable decay product after15,000 years?(The shaded region representsradioactive material while the non-shaded regionrepresents stable decay products.)

A 18

B 12

C 13

D 14

44. A radioactive element has a half-life of 2 days. Whichfraction represents the amount of an original sample ofthis element remaining after 6 days?

A 8.0 g B 16 g C 32 g D 4.0 g

45. A sample of 131I decays to 1.0 gram in 40. days. Whatwas the mass of the original sample?

A 94Be + 42He 126C + 10nB U + 3 F2 UF6C Mg(OH)2 + 2 HCl 2 H2O + MgCl2D Ca + 2 H2O Ca(OH)2 + H2

46. Which equation is an example of artificialtransmutation?

A natural transmutationB artificial transmutationC natural decayD radioactive decay

47. The change that is undergone by an atom of an elementmade radioactive by bombardment with high-energyprotons is called

A addition B neutralizationC substitution D transmutation

48. Which type of reaction occurs when a high-energyparticle collides with the nucleus of an atom,converting that atom to an atom of a different element?

ABCD

49. Which equation represents a transmutation reaction?

A a fission reactionB a chain reactionC an artificial transmutationD a natural transmutation

50. The reaction:

14 7N + 42He ® 17 8O + 11H

Is an example of

A fission B fusionC natural decay D endothermic

51. Given the nuclear reaction:

235 92U + 10n ® 138 56Ba + 9536Kr + 310n + energy

This equation can best be described as

A operation of a fission nuclear reactorB explosion of an atomic bombC production of energy by the Earth's SunD fusion of light nuclei into heavier nuclei

52. An uncontrolled chain reaction takes place during the

A Heavy nuclei split into lighter nuclei.B Light nuclei form into heavier nuclei.C Energy is released and less stable elements are

formed.D Energy is absorbed and more stable elements are

formed.

53. Which statement best describes what happens in afission reaction?

A ionization B crystallizationC combustion D transmutation

54. The spontaneous decay of an atom is called

55. The diagram below represents a nuclear reaction inwhich a neutron bombards a heavy nucleus.

A fission B fusionC alpha decay D beta decay

Which type of reaction does the diagram illustrate?

A combustion B reductionC nuclear fission D nuclear fusion

56. In which type of reaction do two lighter nuclei combineto form one heavier nucleus?

A 23892U + 10n ® 23993Np + 0–1eB 23592U + 10n ® 9236Kr + 14156Ba + 3 10nC 146C ® 147N + 0–1eD 11H + 21H ® 32He

57. Which nuclear equation represents a fusion reaction?

A Matter is converted to energy.B Energy is converted to matter.C Ionic bonds are converted to covalent bonds.D Covalent bonds are converted to ionic bonds.

58. Which change takes place in a nuclear fusion reaction?

A fission, mass converted to energyB fission, energy converted to massC fusion, mass converted to energyD fusion, energy converted to mass

59. Given the balanced equation representing a nuclearreaction:

Which phrase identifies and describes this reaction?

A slow oxidation B rapid oxidationC fission D fusion

60. For a given mass of reactants, the energy released isgreatest for a reaction involving

A 0+1e B 0–1e C 10n D 11H

61. In the equation:

23940Th ® 234 91Pa + X

The symbol X represents

A 3013Al B 3014SiC 3015P D 3016S

62. Given the reaction:

2713Al + 42He ® X + 10n

When the equation is correctly balanced, the nucleusrepresented by X is

A 93Li B 105B C 94Be D 106C

63. In the reaction:

X + 11H ® 63Li + 42He

The nucleus represented by X is

A an alpha particle B a beta particleC an electron D a proton

64. A neutron has approximately the same mass as

A 0+1e B 11H C 0–1e D 10n

65. In the reaction:

94Be + X ® 63Li + 42He

The X represents

A 23492U B 23592UC 23090Th D 23290Th

66. Given the reaction:

23491Pa ® X + 0–1e

When the equation is correctly balanced the nucleusrepresented by X is

A 83Li B 63Li C 85B D 105B

67. Given the reaction:

94Be + 11H ® 42He + X

Which species is represented by X?

A 0–1e B 11H C 21H D 10n

68. Given the equation: 147N + 42He ® X + 178OWhen the equation is balanced correctly, which particleis represented by X?

69. Base your answer to the following question on Giventhe nuclear equation:

A B C D

Which particle is represented by ?

A 3115P B 3215P C 3116P D 3216P

70. Given the nuclear reaction:

3216S + 10n 11H + X

What does X represent in this reaction?

A collisions between nuclei of high atomic numberB collisions between nuclei of low atomic numberC the conversion of mass to energyD the conversion of energy to mass

71. A fission reaction is similar to a fusion reaction in thatboth reactions involve

A breaking of bonds between atomsB formation of bonds between atomsC conversion of mass into energyD conversion of energy into mass

72. The energy released by a nuclear reaction resultsprimarily from the

A formation of covalent bondsB formation of ionic bondsC conversion of matter to energyD conversion of energy to matter

73. Energy is released during the fission of Pu-239 atomsas a result of the

A form heavy nuclides from light nuclidesB form light nuclides from heavy nuclidesC release a large amount of energyD absorb a large amount of energy

74. A nuclear fission reaction and a nuclear fusion reactionare similar because both reactions

A a conversion of some of the reactant's massB a loss of potential energy by the reactantsC the fusion of two nucleiD the fission of a nucleus

75. Compared to a nuclear reaction, a chemical reactiondiffers in that the energy produced by a chemicalreaction results primarily from

A mass is converted into energyB energy is converted into massC ionic bonds are brokenD covalent bonds are broken

76. The amount of energy released from a fission reactionis much greater than the energy released from achemical reaction because in a fission reaction

A less than the mass of the reactants becausesome of the mass has been converted to energy

B less than the mass of the reactants because someof the energy has been converted to mass

C more than the mass of the reactants because someof the mass has been converted to energy

D more than the mass of the reactants because someof the energy has been converted to mass

77. In a nuclear fusion reaction, the mass of the products is

A a conversion of some of the reactant's massB the formation of chemical bonds by the reactantsC the loss of kinetic energy of the reactantsD the splitting of a nucleus

78. The energy released in a fusion reaction comes from

A accelerating to increase kinetic energyB radiating to kill cancer cellsC counting to determine a level of radioactivityD dating to determine age

79. Which procedure is based on the half-life of aradioisotope?

A uranium-235 to uranium-238B hydrogen-2 to hydrogen-3C nitrogen-16 to nitrogen-14D carbon-14 to carbon-12

80. Which isotopic ratio needs to be determined when theage of ancient wooden objects is investigated?

A 14C B 16N C 32P D 37K

81. Which isotope is most commonly used in theradioactive dating of the remains of organic materials?

A uranium-238 B iodine-131C cobalt-60 D technetium-99

82. Which radioactive isotope is used in geological dating?

A Rn-222 B I-131C Co-60 D C-14

83. The decay of which radioisotope can be used toestimate the age of the fossilized remains of an insect?

A carbon-12 B carbon-13C carbon-14 D carbon-15

84. Which element is used for dating archaeologicaldiscoveries?

A C-14 and C-12 B Co-60 and Co-59C I-131 and Xe-131 D U-238 and Pb-206

85. Which nuclides are used to date the remains of aonce-living organism?

A 206Pb B 206Bi C 214Pb D 214Bi

86. A radioactive-dating procedure to determine the age ofa mineral compares the mineral's remaining amounts ofisotope 238U and isotope

A determining the age of a sampleB determining medical disordersC controlling fission reactionsD controlling speeds of neutrons

87. The radioactive isotope carbon-14 can be used for

A carbon-14 B cobalt-60C lead-206 D uranium-238

88. Which radioactive isotope is used in treating cancer?

A Co-60 B I-131C C-14 D U-238

89. Which radioisotope is used to treat thyroid disorders?

A control nuclear reactorsB determine the age of fossilsC diagnose thyroid disordersD trigger fussion reactors

90. The radioisotope I-131 is used to

A U-238 B Pb-206C I-131 D Co-60

91. Which radioisotope is used for diagnosing thyroiddisorders?

A increase the rate of nutrient decompositionB kill microorganisms that are found in the foodC convert ordinary nutrients to more stable formsD replace chemical energy with nuclear energy

92. Radiation used in the processing of food is intended to

A N-16 B Sr-9OC Cs-137 D Pu-239

93. According to Table N, which radioactive waste can bestored for decay and then safely released directly intothe environment?

A nuclear reactor meltdownsB storage of waste materialsC biological exposureD production of energy

94. One benefit of nuclear fission reactions is

A depletion of hydrocarbonsB depletion of atmospheric oxygenC exposure of workers to radiationD exposure of workers to sulfur dioxide

95. Which risk is associated with using nuclear fission toproduce energy in a power plant?

A A small quantity of energy is produced.B Reaction products contribute to acid rain.C It is impossible to control nuclear fission.D It is difficult to dispose of wastes.

96. What is a problem commonly associated with nuclearpower facilities?

A acid rainB helium gasC greenhouse gases, such as CO2D radioisotopes with long half-lives

97. A serious risk factor associated with the operation of anuclear power plant is the production of

A fusion of tritium and deuteriumB fission of uraniumC burning of heating oilD burning of wood

98. Which type of reaction produces energy and intenselyradioactive waste products?

A They frequently have short half-lives and remainradioactive for brief periods of time.

B They frequently have short half-lives and remainradioactive for extended periods of time.

C They frequently have long half-lives and remainradioactive for brief periods of time.

D They frequently have long half-lives andremain radioactive for extended periods oftime.

99. Which statement explains why nuclear waste materialsmay pose a problem?

A radon-222 B radium-226C cesium-137 D cobalt-60

100. Refering to Table N, which substance is a radioactivewaste product that is safest to release into theatmosphere after it has decayed to a safe radiationlevel?

A coolants B control rodsC moderators D fuels

101. Fissionable uranium-233, uranium-235, andplutonium-239 are used in nuclear reactors as

A moderators B control rodsC coolants D shielding

102. The fission process in a reactor can be regulated byadjusting the number of neutrons available. This isdone by the use of

A shielding B coolantsC moderators D control rods

103. The temperature levels in a nuclear reactor aremaintained primarily by the use of

A heavy water B carbon dioxideC graphite D helium

104. Which substance can be used as both a coolant and amoderator in a nuclear reactor?

A absorb neutronsB emit neutronsC decrease the speed of neutronsD increase the speed of neutrons

105. Control rods in nuclear reactors are commonly madeof boron and cadmium because these two elementshave the ability to

A B(s) B Cd(s)C H2(g) D Na( )

106. Which substance is used as a coolant in a fissionreactor?

107. The diagram below represents a nuclear reactor. Thearrows indicate the direction of the flow of water.

A turbine B moderatorC control rod D internal shield

Which structure is indicated by letter A?

A cooling system B control rodsC moderator D shielding

108. In which component of a fission reactor is the elementcadmium used?

A nitrogen-16 B thorium-232C uranium-235 D plutonium-239

109. Which is a gaseous radioactive waste produced duringsome fission reactions?

A water and concreteB graphite and berylliumC cadmium and boronD sodium and carbon dioxide

110. Which substances are used in the control rods ofnuclear reactors?

111. Base your answer to the following question on the information below.

In the early 1800s, John Dalton proposed an atomic theory that was based on experimental observationsmade by several scientists. Three concepts of Dalton’s atomic theory are stated below.

Statement A: Atoms are indivisible and cannot be destroyed or broken down into smaller parts. Statement B: Atoms of one element cannot be changed into atoms of another element. Statement C: All atoms of one element have the same mass.Explain, in terms of particles in the atoms of an element, why statement C is false.

112. Base your answer to the following question on the information below.

A substance known as heavy water can be obtained from ordinary water and could be a significantsource of energy in the future. Heavy water contains deuterium, H-2. Instead of the two hydrogen atomsin a typical water molecule, a heavy water molecule has two deuterium atoms. In 3.78 kilograms ofordinary water, the percent composition by mass of heavy water is approximately 0.0156%. Deuterium atoms completely ionize at approximately 108 K. The result is an ionized gas consisting ofelectrons and deuterons (the nuclei of deuterium). A triton is the nucleus of a tritium atom, H-3. Theseparticles react according to the equations below. In the second equation, X represents an unidentifiedproduct.

21H + 21H ® 31H + 11H + energy21H + 31H ® 42He + X + energy

Identify particle X in the second nuclear equation. Your response must include the symbol, atomicnumber, and mass number of the particle.

113. Base your answer to the following question on the information below.

Polonium-210 occurs naturally, but is scarce. Polonium-210 is primarily used in devices designed toeliminate static electricity in machinery. It is also used in brushes to remove dust from camera lenses. Polonium-210 can be created in the laboratory by bombarding bismuth-209 with neutrons to createbismuth-210. The bismuth-210 undergoes beta decay to produce polonium-210. Polonium-210 has ahalf-life of 138 days and undergoes alpha decay.State one beneficial use of Po-210.

Base your answers to questions 114 and 115 on the information below.

The radioisotopes carbon-14 and nitrogen-16 are present in a living organism. Carbon-14 iscommonly used to date a once-living organism.

114. Complete the nuclear equation for the decay of C-14. Include both the atomic number and the massnumber of the missing particle.

115. A sample of wood is found to contain 1/8 as much C-14 as is present in the wood of a living tree. What isthe approximate age, in years, of this sample of wood?

116. Base your answer to the following question on the information below.

Some radioisotopes used as tracers make it possible for doctors to see the images of internal bodyparts and observe their functions. The table below lists information about three radioisotopes and thebody part each radioisotope is used to study.

Write the equation for the nuclear decay of the radioisotope used to study red blood cells. Include both the atomic number and the mass number for each missing particle.

59Fe ® ____ + ____ + energy

117. Base your answer to the following question on the information below.

Cobalt-60 is commonly used as a source of radiation for the prevention of food spoilage. Bombardingcobalt-59 nuclei with neutrons produces the nuclide cobalt-60. A food irradiation facility replaces thecobalt-60, a source of gamma rays, when the radioactivity level falls to of its initial level. Thenuclide cesium-137 is also a source of radiation for the prevention of food spoilage.

Complete the nuclear equation below for the decay of cesium-137. Your response must include thesymbol, atomic number, and mass number of the missing particle.

Base your answers to questions 118 and 119 on the article below, the Reference Tables for PhysicalSetting/Chemistry, and your knowledge of chemistry.

In the 1920s, paint used to inscribe the numbers on watch dials was composed of aluminescent (glow-in-the-dark) mixture. The powdered-paint base was a mixture of radiumsalts and zinc sulfide. As the paint was mixed, the powdered base became airborne and driftedthroughout the workroom causing the contents of the workroom, including the painters’clothes and bodies, to glow in the dark. The paint is luminescent because radiation from the radium salts strikes a scintillator. Ascintillator is a material that emits visible light in response to ionizing radiation. In watch dialpaint, zinc sulfide acts as the scintillator. Radium present in the radium salts decomposes spontaneously, emitting alpha particles.These particles can cause damage to the body when they enter human tissue. Alpha particlesare especially harmful to the blood, liver, lungs, and spleen because they can alter geneticinformation in the cells. Radium can be deposited in the bones because it substitutes forcalcium.

118. Write the notation for the alpha particles emitted by radium in the radium salts.

119. How can particles emitted from radioactive nuclei damage human tissue?

120. Base your answer to the following question on the information below, which relates the numbers ofneutrons and protons for specific nuclides of C, N, Ne, and S.

Based on your Reference Tables, complete the decay equation for N-16:

16 7 N ® ______ + ______

121. Given the nuclear equation:

23592U + 10n 14256Ba + 9136Kr + 310n + energya State the type of nuclear reaction represented by theequation.b The sum of the masses of the products is slightly lessthan the sum of the masses of the reactants. Explainthis loss of mass.c This process releases greater energy than an ordinarychemical reaction does. Name another type of nuclearreaction that releases greater energy than an ordinarychemical reaction.

Base your answers to questions 122 through 124 on theinformation below.

The radioisotope uranium-238 occurs naturally inEarth's crust. The disintegration of this radioisotope isthe first in a series of spontaneous decays. The sixth decay in this series produces theradioisotope radon-222. The decay of radon-222produces the radioisotope polonium-218 that has a halflife of 3.04 minutes. Eventually, the stable isotopelead-206 is produced by the alpha decay of an unstablenuclide.

122. Determine the original mass of a sample of Po-218, if0.50 milligram of the sample remains unchanged after12.16 minutes.

123. Explain, in terms of electron configuration, why atomsof the radioisotope produced by the sixth decay in theU-238 disintegration series do not readily react toform compounds.

124. Complete the nuclear equation below for the decay ofthe unstable nuclide that produces Pb-206, by writinga notation for the missing nuclide.

_________________® 42He + 20682Pb

Base your answers to questions 125 and 126 on the article below, the Reference Tables forPhysicalSetting/Chemistry, and your knowledge of chemistry.

Radioactivity at home You may be surprised to learn that you do not need to visit a nuclear power plant or ahospital X-ray laboratory to find sources of radioactivity. They are all around us. In fact, it islikely that you’ll find a few at home. Your front porch may incorporate cinder blocks orgranite blocks. Both contain uranium. Walk through the front door, look up, and you’ll see asmoke detector that owes its effectiveness to the constant source of alpha particle emissionsfrom Americium-241. As long as the gases remain ionized within the shielded container,electricity flows, and all is calm. When smoke enters the chamber, it neutralizes the chargeson these ions. In the absence of these ions, the circuit breaks and the alarm goes off. Indicator lights on your appliances may use Krypton-85; electric blankets,promethium-147; and fluorescent lights, thorium-229. Even the food we eat is radioactive.The more potassium-rich the food source, the more potassium-40—a radioactive isotope thatmakes up about 0.01% of the natural supply of this mineral—is present. Thus, brazil nuts,peanuts, bananas, potatoes, and flour, all rich in potassium, are radiation sources.—Chem Matters April 2000

125. State one risk or danger associated with radioactivity.

126. How is the radioactive decay of Krypton-85 different from the radioactive decay of Americium-241?

127. Base your answer to the following question on theinformation below, the Reference Tables forChemistry, and your knowledge of chemistry. Radioactivity and radioactive isotopes have thepotential for both benefiting and harming livingorganisms. One use of radioactive isotopes is inradiation therapy as a treatment for cancer.Cesium-137 is sometimes used in radiation therapy. A sample of cesium-137 was left in an abandonedclinic in Brazil in 1987. Cesium-137gives off a blueglow because of its radioactivity. The people whodiscovered the sample were attracted by the blue glowand had no idea of any danger. Hundreds of peoplewere treated for overexposure to radiation, and fourpeople died.Using Reference Table N, complete the equationprovided in your answer booklet for the radioactivedecay of 13755Cs. Include both atomic number andmass number for each particle.

128. Base your answer to the following question on the reading passage below and on your knowledge ofchemistry.

A Glow in the Dark, and Scientific Peril The [Marie and Pierre] Curies set out to study radioactivity in 1898. Their first accomplishment was toshow that radioactivity was a property of atoms themselves. Scientifically,that was the most important oftheir findings, because it helped other researchers refine their understanding of atomic structure. Morefamous was their discovery of polonium and radium. Radium was the most radioactive substance theCuries had encountered. Its radioactivity is due to the large size of the atom, which makes the nucleusunstable and prone to decay, usually to radon and then lead, by emitting particles and energy as it seeks amore stable configuration.Marie Curie struggled to purify radium for medical uses, including earlyradiation treat-ment for tumors. But radiums bluish glow caught peoples fancy, and companies intheUnited States began mining it and selling it as a novelty: for glow-in-the-dark light pulls, for instance,and bogus cure-all patent medicines that actually killed people.What makes radium so dangerous is that itforms chemical bonds in the same way as calcium, and the body can mistake it for calcium and absorb itinto the bones. Then, it can bombard cells with radiation at close range, which may cause bone tumors orbone-marrow damage that can give rise to anemia or leukemia. - Denise Grady, The New York Times, October 6, 1998State one risk associated with the use of Radium.

129. Base your answer to the following question on the information below and on your knowledge ofchemistry.

Nuclear Waste Storage Plan for Yucca Mountain In 1978, the U.S. Department of Energy began a study of Yucca Mountain which is located 90 milesfrom Las Vegas, Nevada. The study was to determine if Yucca Mountain would be suitable for along-term burial site for high-level radioactive waste. A three-dimensional (3-D) computer scale model ofthe site was used to simulate the Yucca Mountain area. The computer model study for Yucca Mountainincluded such variables as: the possibility of earthquakes, predicted water flow through the mountain,increased rainfall due to climate changes, radioactive leakage from the waste containers, and increasedtemperatures from the buried waste within the containers. The containers that will be used to store the radioactive waste are designed to last 10,000 years. Withinthe 10,000-year time period, cesium and strontium, the most powerful radioactive emitters, would havedecayed. Other isotopes found in the waste would decay more slowly, but are not powerful radioactiveemitters. In 1998, scientists discovered that the compressed volcanic ash making up Yucca Mountain was full ofcracks. Because of the arid climate, scientists assumed that rainwater would move through the cracks at aslow rate. However, when radioactive chlorine-36 was found in rock samples at levels halfway throughthe mountain, it was clear that rainwater had moved quickly down through Yucca Mountain. It was only50 years earlier when this chlorine-36 isotope had contaminated rainwater during atmospheric testing ofthe atom bomb. Some opponents of the Yucca Mountain plan believe that the uncertainties related to the manyvariables of the computer model result in limited reliability of its predictions. However, advocates of theplan believe it is safer to replace the numerous existing radioactive burial sites around the United Stateswith the one site at Yucca Mountain. Other opponents of the plan believe that transporting the radioactivewaste to Yucca Mountain from the existing 131 burial sites creates too much danger to the United States.In 2002, after years of political debate, a final legislative vote approved the development of YuccaMountain to replace the existing 131 burial sites.Why is water flow a crucial factor in deciding whether Yucca Mountain is a suitable burial site?

130. Base your answer to the following question on in the information below.

When a uranium-235 nucleus absorbs a slow-moving neutron, different nuclear reactions mayoccur. One of these possible reactions is represented by the complete, balanced equation below.

Equation 1: 23592U + 10n ® 9236Kr + 14256Ba + 210n + energy

For this reaction, the sum of the masses of the products is slightly less than the sum of themasses of the reactants. Another possible reaction of U-235 is represented by the incomplete,balanced equation below.

Equation 2: 23592U + 10n ® 9238Sr + ____ + 210n + energyWrite a notation for the missing product in equation 2.

Answer KeyNuclear Chemistry extra

1. A2. A3. A4. A5. A6. A7. A8. C9. A10. A11. D12. B13. D14. A15. C16. D17. D18. A19. B20. D21. C22. A23. C24. B25. C26. C27. B28. C29. A30. D31. C32. A33. A34. B35. C36. B

37. D38. C39. D40. D41. C42. C43. C44. A45. C46. A47. B48. D49. B50. C51. A52. B53. A54. D55. A56. D57. D58. A59. C60. D61. B62. C63. C64. D65. B66. A67. B68. B69. A70. B71. C72. C

73. C74. C75. B76. A77. A78. A79. D80. D81. A82. A83. D84. C85. A86. A87. A88. B89. B90. C91. C92. B93. A94. D95. C96. D97. D98. B99. D100. A101. D102. B103. B104. A105. A106. D107. C108. B

109. A110. C111. Acceptable responses

include, but are notlimited to: • Atoms ofdifferent isotopes ofan element havedifferent massesbecause they havedifferent numbers ofneutrons. • Atoms ofan element can differin the number ofneutrons and,therefore, masses.

112. 10n113. – Polonium-210 is

used to eliminatestatic electricity inmachinery. – removesdust from cameralenses

114. 14 N 7

115. 17,190 years or 3(5730) years

116. Examples: 5926FE ® 0–1e + 5927Co or 5926Fe ® 5927Co + 0–1

117. 173 56Ba118.

Answer KeyNuclear Chemistry extra

119. Examples: –Emittedparticles alter geneticinformation. –changeDNA

120. 0 –1 e + 16 8 O121. a fission

b Example:The mass is convertedto energy.c Examples:fusion – nucleardecay – radioactivedecay – naturaltransmutation

122. 8.00 mg.123. –Radon-222 atoms

have a complete outershell of electrons andtend not to bond.–There are eightvalence electrons in aradon atom.–Octet in valenceshell.

124. 21084Po or 210Po orPo-210

125. Acceptable responses:Extensive exposurecan make people sick,contamination ofenvironment,introduction ofradioactive materialsinto the ecosystem

126. Acceptable responses:85Kr undergoes betadecay and 241Amundergoes alphadecay, Decay modeand half-life aredifferent, half-livesdifferent.

127. Responses include,but are not limited to,these examples: 13755Cs ® 0–1e + 13756Ba • 13755Cs ® 0–1 + 13756Ba

128. cause bone tumors or damage bone marrowor can cause leukemiaor anemia or radioactive or DNAdamage or death

129. Examples: – becausewater may transportthe radioactivematerials; – causecontainers to corrode

130. xenon-142 or 14254Xe