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Chemistry: The Central Science, 13e (Brown et al.)
Chapter 21 Nuclear Chemistry
21.1 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 changes.
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) e
B) β
C) e
D) e
E) β
5) Which one of the following is a correct representation of an alpha particle?
A) He
B) H
C) H
D) e
E) H
6) Which one of the following is a correct representation of a positron?
A) e
B) β
C) e
D) e
E) β
7) 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
8) 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.
9) 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) thorium-234
10) 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
11) 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
12) Alpha decay produces a new nucleus whose ________ than those respectively of the original nucleus.
A) atomic number is 2 less and mass number is 2 less
B) atomic number is 1 less and mass number is 2 less
C) atomic number is 2 less and mass number is 4 less
D) atomic number is 2 more and mass number is 4 more
E) atomic number is 2 more and mass number is 2 less
13) What is the missing product from this reaction?
P → S + _____
A) He
B) e
C) γ
D) e
E) p
14) What is the atomic number of a neutron?
A) 3
B) 1
C) 2
D) 0
E) 4
15) 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.
16) Atoms with the same atomic number and different mass numbers ________.
A) do not exist
B) are isomers
C) are isotopes
D) are allotropes
E) are resonance structures
17) How many radioactive decay series exist in nature?
A) 0
B) 1
C) 2
D) 3
E) 10
18) 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
19) Carbon-11 decays by ________.
A) alpha emission
B) beta emission
C) positron emission
D) photon emission
E) neutron capture
20) The formation of krypton from rubidium decay is a result of ________.
A) alpha emission
B) beta emission
C) positron emission
D) electron capture
E) neutron capture
21) The mode of decay of 32P is ________.
A) alpha emission
B) beta emission
C) positron emission
D) electron capture
E) neutron capture
22) The belt of nuclear stability ends with the element ________.
A) lead
B) polonium
C) radon
D) astatine
E) bismuth
23) Which of these nuclides is most likely to be radioactive?
A) K
B) Al
C) I
D) Am
E) Bi
24) 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 or neutron
D) spontaneous nuclear decay
E) gamma emission
25) In the nuclear transmutation, O (p, α) N, what is the bombarding particle?
A) an alpha particle
B) a beta particle
C) a gamma photon
D) a proton
E) a phosphorus nucleus
26) 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
27) 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
28) Transuranium elements have atomic numbers greater than ________.
A) 90
B) 91
C) 92
D) 93
E) 94
9
29) What is emitted in the nuclear transmutation, Al(n, ?) Na?
A) an alpha particle
B) a beta particle
C) a neutron
D) a proton
E) a gamma photon
30) In the nuclear transmutation represented by Pu( He, n)?, what is the product?
A) uranium-242
B) curium-245
C) curium-242
D) uranium-245
E) uranium-243
31) In the nuclear transmutation represented by N( n, p)?, what is the emitted particle?
A) neutron
B) proton
C) positron
D) alpha particle
E) electron
32) In the nuclear transmutation represented by N( n, p)?, what is the product?
A) carbon-12
B) carbon-16
C) carbon-14
D) nitrogen-16
E) nitrogen-15
33) Which one of the following requires a particle accelerator to occur?
A) Fe → Co + e
B) Co + n → Co
C) U + n → Np + e
D) Pu + He → Cm + n
E) none of the above
34) Bombardment of uranium-238 with a deuteron (hydrogen-2) generates neptunium-237 and ________
neutrons.
A) 1
B) 2
C) 3
D) 4
E) 5
35) Which of the following correctly represents the transmutation in which neptunium-239 is produced
via bombardment of uranium-238 with a neutron?
A) U( n, e) Np
B) U( n, p) Np
C) U( n, γ) Np
D) U( n, α) Np
E) U( n, n) Np
36) 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) Cm( He, n) Cf
B) Cm( He, p) Cf
C) Cm( He, e) Cf
D) Cm( n, He) Cf
E) Cm( He, 2 p) Cf
37) 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 UF6
D) oxidize it to the +2 oxidation state
E) none of the above
38) 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
39) The half-life of 218Po is 3.1 minutes. How much of a 155 gram sample remains after 0.40 hours?
A) 0.00067 g
B) 0.0072 g
C) 0.72 g
D) 0.0047 g
E) none of the above
40) Cesium-131 has a half-life of 9.7 days. What percent of a cesium-131 sample remains after 60 days?
A) 100
B) 0
C) 1.4
D) 98.6
E) more information is needed to solve the problem
41) 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
42) The half-life of carbon-11 is 20.3 minutes. How much of a 100.0 mg sample remains after 1.50 hours?
A) 8.48 mg
B) 4.63 mg
C) 12.9 mg
D) 22.6 mg
E) 7.70 mg
43) The half-life of 131I is 0.220 years. How much of a 500.0 mg sample remains after 24 hours?
A) 496 mg
B) 560 mg
C) 219 mg
D) 405 mg
E) 337 mg
44) The half-life of 223Ra is 11.4 days. How much of a 200.0 mg sample remains after 600 hours?
A) 0.219 mg
B) 21.9 mg
C) .0302 mg
D) 43.8 mg
E) 6.04 mg
45) The half-life of 222Rn is 3.80 days. If a sample contains 36.0 g of Rn-222, how many years will it take
for the sample to be reduced to 1.00 mg of Rn-222?
A) 19.7
B) 0.1597
C) 8.53
D) 0.0234
E) none of the above
46) 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
47) 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.
48) 210Pb has a half-life of 22.3 years and decays to produce 206Hg. 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
49) 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
50) 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:
51) What is the rate constant (in min-1) for the decay of this radionuclide?
A) 45
B) 32
C) 0.024
D) 0.032
E) 0.022
52) What is the half-life (in min) of this radionuclide?
A) 0.024
B) 0.022
C) 32
D) 0.032
E) 45
53) 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) 6.1 × 1013
B) 6.2 × 1022
C) 8.4 × 1015
D) 1.3 × 10-8
E) 8.1 × 1015
54) 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
55) Which one of the following devices converts radioactive emissions to light for detection?
A) Geiger counter
B) photographic film
C) scintillation counter
D) radiotracer
E) none of the above
56) 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
57) 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.
58) The mass of a proton is 1.673 × 10-24 g. The mass of a neutron is 1.675 × 10-24 g. The mass of the
nucleus of an 56Fe atom is 9.289 × 10-23 g. What is the nuclear binding energy (in J) for a 56Fe nucleus?
(c = 3.00 × 108 m/s)
A) 2.57 × 10-16
B) 7.72 × 10-8
C) 8.36 × 10-9
D) 7.65 × 10-11
E) 6.07 × 106
59) When two atoms of 2H are fused to form one atom of 4He, the total energy evolved is 3.83 × 10-12 J.
What is the total change in mass (in kg) for this reaction? (c = 3.00 × 108 m/s)
A) 1.28 × 10-17
B) 4.26 × 10-26
C) 3.45 × 108
D) 1.15
E) 4.26 × 10-29
60) 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 Co nucleus? (The mass of a cobalt-60 nucleus is 59.9338 amu.)
A) 2.74 × 10-19
B) 9.12 × 10-28
C) 4.94 × 10-13
D) 8.20 × 10-11
E) 2.74 × 10-16
61) 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 Co nucleus? (The mass of a cobalt-60 nucleus is 59.9338 amu.)
A) 1.37 × 10-12
B) 3.04 × 10-12
C) 2.49 × 10-12
D) 9.43 × 10-13
E) 7.01 × 10-14
62) 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 Ni 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
63) In terms of binding energy per nucleon, what element divides fission and fusion processes?
A) H
B) He
C) C
D) Fe
E) U
64) What type of reaction is known as a thermonuclear reaction?
A) fission
B) fusion
C) transmutation
D) beta emission
E) neutron emission
65) The main scientific difficulty in achieving a controlled fusion process is the ________.
A) enormous repulsion between nuclei being fused
B) enormous repulsion between the electrons of atoms 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
66) 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
67) 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.
68) 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
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21.2 Bimodal Questions
1) What percentage of electricity generated in the U.S. is from commercial nuclear plants?
A) 1%
B) 10%
C) 19%
D) 50%
E) 90%
2) By what process does thorium-230 decay to radium-226?
A) gamma emission
B) alpha emission
C) beta emission
D) electron capture
E) positron emission
3) The alpha decay of what isotope of what element produces lead-206?
A) polonium-210
B) radon-222
C) mercury-202
D) bismuth-208
E) thallium-204
4) In balancing the nuclear reaction U → E + He, the identity of element E is ________.
A) Pu
B) Np
C) U
D) Pa
E) Th
5) In balancing the nuclear reaction C → E + e, the identity of element E is ________.
