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28) On average, __________ neutrons are produced by every fission of a uranium-235 nucleus.

A) 4 B) 3.5 C) 1 D) 2.4 E) 2

29) What drives the turbine in a nuclear power plant?

A) the moderator B) steam C) the control rods D) the primary coolant E) 6UF gas

30) Who is credited with first achieving fission of uranium-235?

A) Fermi B) Rutherford C) Curie D) Dalton E) Faraday

31) When ionizing radiation enters the body, what is the predominant free radical produced?

A) H B) 3H O C) protein D) OH E) 2H O

32) The nuclear disintegration series of __________ is the source of radon-222 in soil.

A) 235U B) 238U C) 236Pb D) 235Th E) 14C

2 Multiple-Choice Questions

1) All atoms of a given element have the same

A) mass number. B) number of nucleons. C) atomic mass. D) number of neutrons.

E) atomic number.

2) Atoms containing radioactive nuclei are called

A) radionuclides. B) radioisotopes. C) nucleons. D) nuclides. E) radioisophores.

3) What happens to the mass number and the atomic number of an element when it undergoes beta decay?

A) Neither the mass number nor the atomic number change.

B) The mass number decreases by 4 and the atomic number decreases by 2.

C) The mass number does not change and the atomic number increases by 1.

D) The mass number does not change and the atomic number decreases by 2.

E) The mass number increases by 2 and the atomic number increases by 1.

4) Which one of the following is a correct representation of a beta particle?

A) 4e2

B) 1β0

C) 0e1

D) 0e1

E) 2β4

5) Which one of the following processes results in an increase in the atomic number?

A) gamma emission B) positron emission C) beta emission D) alpha emission E) corrosion

6) Of the following processes, which one changes the atomic number?

A) alpha emission B) beta emission C) electron capture D) positron emission

E) All of these processes change the atomic numbers.

7) What radioactive element is used to diagnose medical conditions of the heart and arteries?

A) cobalt-60 B) thallium-201 C) radium-226 D) radon-222 E) Th-234

8) In what type of radioactive decay does the atomic number of the product increase by one?

A) alpha B) beta C) gamma D) positron emission E) electron capture

9) Which type of radioactive decay results in no change in mass number and atomic number for the starting

nucleus?

A) alpha B) beta C) positron emission D) electron capture E) gamma

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10) Alpha decay produces a new nucleus whose __________ than those respectively of the original nucleus.

A) atomic number is 2 less & mass number is 2 less B) atomic number is 1 less & mass number is 2 less

C) atomic number is 2 less & mass number is 4 less D) atomic number is 2 more & mass number is 4 more

E) atomic number is 2 more & mass number is 2 less

11) What is the missing product from this reaction? 32 32P S _____15 16

A) 4He2

B) 0e1

C) 00 D) 0e

1 E) 0p

1

12) What is the atomic number of a neutron?

A) 3 B) 1 C) 2 D) 0 E) 4

13) What happens to the mass number and the atomic number of an element when it emits gamma radiation?

A) The mass number remains unchanged while the atomic number decreases by one.

B) The mass number decreases by four and the atomic number decreases by two.

C) The mass number increases by four and the atomic number increases by two.

D) The mass number remains unchanged while the atomic number increases by one.

E) The mass number and atomic numbers remain unchanged.

14) Atoms with the same atomic number and different mass numbers

A) do not exist. B) isomers. C) are isotopes. D) are allotropes E) are resonance structures.

15) How many radioactive decay series exist in nature?

A) 0 B) 1 C) 2 D) 3 E) 10

16) At approximately what number of protons, or neutrons, does the 1:1 ratio of protons to neutrons start to

produce unstable nuclei?

A) 10 B) 20 C) 30 D) 50 E) 80

17) Carbon-11 decays by __________.

A) alpha emission B) beta emission C) positron emission D) electron capture E) neutron capture

18) The formation of krypton from rubidium decay is a result of __________.


19) The mode of decay of 32P is __________.


20) The belt of nuclear stability ends with the element __________.

A) lead B) polonium C) radon D) astatine E) bismuth

21) Which of these nuclides is most likely to be radioactive?

A) 39K19

B) 27Al13

C) 127I53

D) 243Am95

E) 209Bi83

22) What is required for a nuclear transmutation to occur?

A) very high temperature B) a corrosive environment C) a particle to collide with a nucleus

D) spontaneous nuclear decay E) gamma emission

23) In the nuclear transmutation, 16 13O(p, ) N

8 7 , what is the bombarding particle?

A) an alpha particle B) a beta particle C) a gamma photon D) a proton E) a phosphorus nucleus

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24) Cobalt-60 is produced by a three reaction process involving neutron capture, beta-emission, and neutron

capture. The initial reactant in the production of cobalt-60 is __________.

A) 59Co B) 56Fe C) 58Fe D) 61Co E) 60Fe

25) The product of the nuclear reaction in which 28Si is subjected to neutron capture followed by alpha

emission is _________.

A) 31S B) 33S C) 23Mg D) 25Mg E) 25Al

26) Transuranium elements have atomic numbers greater than __________.

A) 90 B) 91 C) 92 D) 93 E) 94

27) What is emitted in the nuclear transmutation, 27 24Al(n, ?) Na13 11

?

A) an alpha particle B) a beta particle C) a neutron D) a proton E) a gamma photon

28) In the nuclear transmutation represented by 239 4 1Pu( He, n)?94 2 0

, what is the product?

A) uranium-242 B) curium-245 C) curium-242 D) uranium-245 E) uranium-243

29) In the nuclear transmutation represented by14 1 1N( n, p)?7 0 1

, what is the emitted particle?

A) neutron B) proton C) positron D) alpha particle E) electron

30) In the nuclear transmutation represented by14 1 1N( n, p)?7 0 1

, what is the product?

A) carbon-12 B) carbon-16 C) carbon-14 D) nitrogen-16 E) nitrogen-15

31) Which one of the following requires a particle accelerator to occur?

A) 59 59 0Fe Co e26 27 1

B) 59 1 60Co n Co27 0 27

C) 238 1 239 0U n Np e92 0 93 1

D) 239 4 242 1Pu He Cm n94 2 96 0

E) none of the above

32) What are the "dees" on a particle accelerator?

A) vibration places B) transmutated bees C) electrodes D) magnets E) targets

33) Bombardment of uranium-238 with a deuteron (hydrogen-2) generates neptunium-237 and _____ neutrons.

A) 1 B) 2 C) 3 D) 4 E) 5

34) Which of the following correctly represents the transmutation in which neptunium-239 is produced via

bombardment of uranium-238 with a neutron?

A) 238 1 0 239U( n, e) Np92 0 1 93

B) 238 1 1 239U( n, p) Np92 0 1 93

C) 238 1 239U( n, ) Np92 1 93

D) 238 1 4 239U( n, ) Np92 0 2 93

E) 238 1 1 239U( n, n) Np92 0 0 92

35) Which of the following correctly represents the transmutation in which a curium-242 nucleus is bombarded

with an alpha particle to produce a californium-245 nucleus?

A) 242 4 1 245Cm( He, n) Cf96 2 0 98

B) 242 4 1 245Cm( He, p) Cf96 2 1 98

C) 242 4 1 245Cm( He, e) Cf96 2 1 98

D) 242 1 4 245Cm( n, He) Cf96 0 2 98

E) 242 4 1 245Cm( He, 2 p) Cf96 2 1 98

36) Which one of the following can be done to shorten the half-life of the radioactive decay of uranium-238?

A) freeze it B) heat it C) convert it to 6UF D) oxidize it to the +2 oxidation state

E) none of the above

37) The beta decay of cesium-137 has a half-life of 30.0 years. How many years must pass to reduce a 25 mg

sample of cesium 137 to 8.7 mg?

A) 46 B) 32 C) 3.2 D) 50 E) 52

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38) The half-life for beta decay of strontium-90 is 28.8 years. A milk sample is found to contain 10.3 ppm

strontium-90. How many years would pass before the strontium-90 concentration would drop to 1.0 ppm?

A) 92.3 B) 0.112 C) 186 D) 96.9 E) 131

39) The half-life of 131I is 0.50 years. How much of a 500.0 mg sample remains after 4 years?

A) 375 mg B) 560 mg C) 250 mg D) 125 mg E) 450 mg

40) The carbon-14 dating method can be used to determine the age of a

A) flint arrowhead. B) papyrus scroll. C) stone axe head. D) clay pot. E) rock.

41) The basis for the carbon-14 dating method is that

A) the amount of carbon-14 in all objects is the same.

B) carbon-14 is very unstable and is readily lost from the atmosphere.

C) the ratio of carbon-14 to carbon-12 in the atmosphere is a constant.

D) living tissue will not absorb carbon-14 but will absorb carbon-12.

E) All of the above are correct.

42) 210Pb has a half-life of 22.3 years and decays to produce206Hg. If you start with 7.50 g of 210Pb, how

many grams of 206Hg will you have after 17.5 years?

A) 4.35 B) 3.15 C) 3.09 D) 0.0600 E) 1.71

43) The half-life of a radionuclide

A) is constant. B) gets shorter with passing time. C) gets longer with passing time.

D) gets shorter with increased temperature. E) gets longer with increased temperature.

44) The curie is a measure of the

A) number of disintegrations per second of a radioactive substance.

B) total energy absorbed by an object exposed to a radioactive source.

C) lethal threshold for radiation exposure.

D) number of alpha particles emitted by exactly one gram of a radioactive substance.

E) None of the above is correct.

Consider the following data for a particular radionuclide:

45) What is the rate constant (in 1min ) for the decay of this radionuclide?

A) 45 B) 31 C) 0.024 D) 0.032 E) 0.022

46) What is the half-life (in min) of this radionuclide?

A) 0.024 B) 0.022 C) 31 D) 0.032 E) 45

47) Cesium-137 undergoes beta decay and has a half-life of 30.0 years. How many beta particles are emitted by

a 14.0-g sample of cesium-137 in three minutes?

A) 136.1 10 B) 226.2 10 C) 158.4 10 D) 81.3 10 E) 158.1 10

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48) What is a phosphor?

A) an oxide of phosphorus B) a substance that thermally reduces to phosphorus

C) a bioluminescent substance D) a substance that emits light when excited by radiation

E) an alkali metal phosphide

49) Which one of the following devices converts radioactive emissions to light for detection?

A) Geiger counter B) photographic film C) scintillation counter D) none of the above

E) radiotracer

50) Which one of the following is used as a radiotracer to study blood?

A) iron-59 B) technetium-99 C) sodium-23 D) iodine-131 E) phosphorus-32

51) Which one of the following is true?

A) Some spontaneous nuclear reactions are exothermic.

B) Some spontaneous nuclear reactions are endothermic.

C) All spontaneous nuclear reactions are exothermic.

D) There is no relationship between exothermicity and spontaneity in nuclear reactions.

E) All spontaneous nuclear reactions are endothermic.

52) The mass of a proton is 241.673 10 g . The mass of a neutron is 241.675 10 g . mass of the nucleus of an

56Fe atom is 239.289 10 g . What is the nuclear binding energy (in J) for a 56Fe nucleus? 8(C 3.00 10 m s)

A) 162.57 10 B) 87.72 10 C) 98.36 10 D) 117.72 10 E) 66.07 10

53) When two atoms of 2H are fused to form one atom of 4He, the total energy evolved is 123.83 10 J What is

the total change in mass (in kg) for this reaction? 8(C 3.00 10 m s)

A) 171.28 10 B) 264.26 10 C) 83.45 10 D) 1.15 E) 294.26 10

54) The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu. What is the binding energy (in J)

of a 60Co27

nucleus? (The mass of a cobalt-60 nucleus is 59.9338 amu.)

A) 192.74 10 B) 289.12 10 C) 134.94 10 D) 118.20 10 E) 162.74 10

55) The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu. What is the binding energy per

nucleon (in J) of a 60Co27

nucleus? (The mass of a cobalt-60 nucleus is 59.9338 amu.)

A) 121.37 10 B) 123.04 10 C) 122.49 10 D) 139.43 10 E) 147.01 10

56) The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu. What is the mass defect (in amu)

of a 60Ni29

nucleus? (The mass of a nickel-60 nucleus is 59.9308 amu.)

A) 0.5449 B) 1.2374 C) 0.5491 D) 28.7930 E) 1.3066

57) In terms of binding energy per nucleon, what element divides fission and fusion processes?

A) H B) He C) C D) Fe E) U

58) What type of reaction is known as a thermonuclear reaction?

A) fission B) fusion C) transmutation D) beta emission E) neutron emission

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59) The main scientific difficulty in achieving a controlled fusion process is the

A) enormous repulsion between the electrons of atoms being fused.

B) enormous repulsion between nuclei being fused. C) very large number of positrons emitted.

D) very large number of x-rays emitted. E) very large number of gamma rays emitted.

60) What exposure level to radiation is fatal to most humans?

A) 100 rem B) 200 rem C) 600 rem D) 300 rem E) 1000 rem

61) Which one of the following is not true concerning radon?

A) It decays by alpha emission. B) It decays to polonium-218, an alpha emitter.

C) It is chemically active in human lungs. D) It has been implicated in lung cancer.

E) It is generated as uranium decays.

62) Which one of the following forms of radiation can penetrate the deepest into body tissue?

A) alpha B) beta C) gamma D) positron E) proton

3 Short Answer Questions

1) What happens in the nucleus of an atom that undergoes positron emission?

2) What is the predominant isotope of uranium?

3) What happens to the atomic mass number and the atomic number of a radioisotope when it undergoes alpha

emission?

4) High speed electrons emitted by an unstable nucleus are called __________.

5) 0e1

represents __________.

6) What isotope of what element is produced if krypton-81 undergoes beta decay?

7) Stable nuclei with low atomic numbers, up to 20, have a neutron to proton ratio of approximately ______.

8) The first nuclear transmutation resulted in the conversion of nitrogen-14 to __________.

9) Conversion of one nucleus into another was first demonstrated in 1919 by __________.

10) The half-life for the beta decay of potassium-40 is 91.3 10 years . What is the rate constant for this decay?

1 2t 0.693/ k 91.3 10 years 0.693/ k 10 1k 5.3 10 year

11) __________ discovered radioactivity. Becquerel

12) Carbon-11, fluorine-18, oxygen-15 and nitrogen-13 are all used in the clinical diagnostic technique known

as __________. positron emission tomography; PET

13) What is the source of the tremendous energies produced by nuclear reactions?

14) Control rods in a nuclear reactor are composed of boron and __________. cadmiun

15) The amount of fissionable material necessary to maintain a chain reactions is called the ___. critical mass

16) When living tissue is irradiated most of the energy is absorbed by __________. water

19) The relative biological effectiveness (RBE) values of beta rays, gamma rays, and alpha rays are,

respectively . 1, 1, 10

20) The major type of cancer caused by radiation is __________. leukemia

21) Radioactive seeds that are implanted into a tumor are coated with __________ to stop alpha and beta ray

penetration. platinum

4 True/False Questions

1) Gamma radiation only changes the atomic number but not the mass number of a nucleus. False

2) Positron emission causes a decrease of one in the atomic number. True

3) The neutron/proton ratio of stable nuclei increases with increasing atomic number. True

4) Charged particles are accelerated because the faster they move there is a greater chance of producing a

nuclear reaction. True

5) Radioactive decay is a first order kinetic process. True

6) In radioactive dating the ratio of carbon-12 to carbon-14 is related to the time of death of the animal or plant

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under investigation. False

7) In the formula 1 2k 0.693/ t , k is the decay constant. True

8) The energy produced by the sun is the result of nuclear fusion. True

9) The SI unit of an absorbed dose of radiation is the gray. True

10) The relative biological effectiveness (RBE) is 10 fold greater for gamma radiation than for alpha radiation.

False

5 Essay Questions

1) Electrons do not exist in the nucleus, yet beta emission is ejection of electrons from the nucleus. How does

this happen?

2) List the common particles and their symbols used in descriptions of radioactive decay and nuclear

transformations.

3) When an isotope undergoes electron capture, what happens to the captured electron?

6 Algorithmic Questions

1) The half-life of cobalt-60 is 5.20 yr. How many milligrams of a 2.000-mg sample remains after 6.55 years?

A) 0.837 B) 153.23 10 C) 4.779 D) 1.588 E) 1.163

2) Strontium-90 is a byproduct in nuclear reactors fueled by the radioisotope uranium-235. The half-life of

Strontium-90 is 28.8 yr. What percentage of a strontium-90 sample remains after 75.0 yr?

A) 68.1 B) 16.5 C) 7.40 D) 38.4 E) 2.60

3) Carbon-11 is used in medical imaging. The half-life of this radioisotope is 20.4 min. What percentage of a

sample remains after 60.0 min?

A) 71.2 B) 5.28 C) 13.0 D) 34.0 E) 2.94

4) A rock contains 0.313 mg of lead-206 for each milligram of uranium-238. The half-life for the decay of

uranium-238 to lead-206 is 94.5 10 yr . The rock was formed __________ yr ago.

A) 91.41 10 B) 91.08 10 C) 91.39 10 D) 92.00 10 E) 91.56 10

5) Potassium-40 decays to argon-40 with a half-life of 91.27 10 yr. The age of a mineral sample that has a

mass ratio of 40Ar to 40K of 0.812 is __________ yr.

A) 91.56 10 B) 91.02 10 C) 91.47 10 D) 87.55 10 E) 91.09 10

6) If we start with 1.000 g of strontium-90, 0.908 g will remain after 4.00 yr. This means that the half-life of

strontium-90 is __________ yr.

A) 3.05 B) 4.40 C) 28.8 D) 3.63 E) 41.6

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7) If we start with 1.000 g of cobalt-60, 0.675 g will remain after 3.00 yr. This means that the half-life of cobalt-

60 is __________ yr.

A) 3.08 B) 4.44 C) 2.03 D) 5.30 E) 7.65

8) A freshly prepared sample of curium-243 undergoes 3312 disintegrations per second. After 6.00 yr, the

activity of the sample declines to 2755 disintegrations per second. The half-life of curium-243 is

__________ yr .

A) 4.99 B) 32.6 C) 7.21 D) 0.765 E) 22.6

9) Carbon-11 decays by positron emission:11 11 0C B e6 5 1

The decay occurs with a release of 112.87 10 J per mole of carbon-11. When 4.00 g of carbon-11 undergoes this

radioactive decay, __________ g of mass is converted to energy.

A) 31.16 10 B) 53.48 10 C) 61.16 10 D) 28.62 10 E) 21.28 10

10) How much energy (in J) is produced when 0.082 g of matter is converted to energy?

A) 187.4 10 B) 127.4 10 C) 42.5 10 D) 157.4 10 E) 72.5 10

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