Deck 18: Nuclear Reactions

Question 1

Complete the following nuclear fission reaction. ${ }_{92}^{235} \mathrm{U}+{ }_{0}^{1} n \rightarrow{ }_{37}^{89} \mathrm{Te}+\ldots 3_{-1}^{0} e+3_{0}^{1} n$

A) ${ }_{52}^{139} \mathrm{Te}$
B) ${ }_{56}^{142} \mathrm{Ba}$
C) ${ }_{55}^{144} \mathrm{Cs}$
D) ${ }_{58}^{144} \mathrm{Ce}$
E) ${ }_{61}^{147} \mathrm{Pm}$

Answer 1

${ }_{58}^{144} \mathrm{Ce}$

Question 2

If a nucleus emits a beta particle,its atomic number

A) decreases by 2.
B) decreases by 1.
C) remains the same.
D) increases by 1.
E) increases by 2.

Answer 2

increases by 1.

Question 3

Complete the following fusion reaction. ${ }_{1}^{3} \mathrm{H}+{ }_{3}^{7} \mathrm{Li} \rightarrow{ }_{0}^{1} n+$ ------

A) ${ }_{4}^{10} \mathrm{Be}$
B) ${ }_{4}^{9} \mathrm{Li}$
C) $2{ }_{2}^{5} \mathrm{He}$
D) ${ }_{2}^{9} \mathrm{He}$
E) ${ }_{4}^{9} \mathrm{Be}$

Answer 3

${ }_{4}^{9} \mathrm{Be}$

Question 4

Which of the following reactions is an example of beta particle emission?

A) ${ }_{42}^{99} \mathrm{Mo} \rightarrow{ }_{43}^{99} \mathrm{Tc}+{ }_{-1}^{0} e$
B) ${ }_{19}^{40} \mathrm{~K}+{ }_{-1}^{0} e \rightarrow{ }_{18}^{40} \mathrm{Ar}$
C) ${ }_{19}^{40} \mathrm{~K} \rightarrow{ }_{18}^{40} \mathrm{Ar}+{ }_{1}^{0} e$
D) ${ }_{92}^{238} \mathrm{U} \rightarrow{ }_{90}^{234} \mathrm{Th}+{ }_{2}^{4} \mathrm{He}$
E) ${ }_{90}^{232} \mathrm{Th} \rightarrow{ }_{88}^{228} \mathrm{Ra}+{ }_{2}^{4} \mathrm{He}$

Question 5

Write the balanced nuclear equation for the formation of ${ }_{14}^{28} \mathrm{Si}$ from beta emission.

A) ${ }_{13}^{28} \mathrm{Al} \rightarrow{ }_{14}^{28} \mathrm{Si}+{ }_{-1}^{0} e$
B) ${ }_{11}^{24} \mathrm{Na}+{ }_{2}^{4} \mathrm{He} \rightarrow{ }_{14}^{28} \mathrm{Si}$
C) ${ }_{15}^{28} \mathrm{P} \rightarrow{ }_{14}^{28} \mathrm{Si}+{ }_{1}^{0} e$
D) ${ }_{15}^{28} \mathrm{P}+{ }_{-1}^{0} e \rightarrow{ }_{14}^{28} \mathrm{Si}$
E) ${ }_{14}^{27} \mathrm{Si}+{ }_{0}^{1} n \rightarrow{ }_{14}^{28} \mathrm{Si}$

Question 6

Which of the following types of radiation will pass through a piece of paper,but will be stopped by 0.5 cm of lead?

A) α
B) β
C)
D) γ
E) All of the above will pass through 0.5 cm of lead.

Question 7

Complete the following nuclear fission reaction. ${ }_{92}^{235} \mathrm{U}+{ }_{0}^{1} n \rightarrow{ }_{56}^{142} \mathrm{Ba}+{ }_{36}^{91} \mathrm{Kr}+$ ------

A) ${ }_{2}^{4} \mathrm{He}$
B) $2_{2}^{4} \mathrm{He}$
C) $3_{1}^{0} e$
D) $3_{-1}^{0} e$
E) $3_{0}^{1} n$

Question 8

If a nucleus decays by successive α,β,β particle emissions,its atomic number will

A) decrease by four.
B) decrease by two.
C) increase by four.
D) increase by two.
E) be unchanged.

Question 9

Write a balanced nuclear equation for the positron emission reaction undergone by ${ }_{6}^{11} \mathrm{C}$ .

A) ${ }_{6}^{11} \mathrm{C} \rightarrow{ }_{5}^{11} \mathrm{~B}+{ }_{0}^{1} n$
B) ${ }_{6}^{11} \mathrm{C} \rightarrow{ }_{6}^{10} \mathrm{C}+{ }_{0}^{1} n$
C) ${ }_{6}^{11} \mathrm{C} \rightarrow{ }_{5}^{11} \mathrm{~B}+{ }_{1}^{0} e$
D) ${ }_{6}^{11} \mathrm{C} \rightarrow{ }_{6}^{13} \mathrm{C}+{ }_{0}^{-1} e$
E) ${ }_{6}^{11} \mathrm{C} \rightarrow{ }_{7}^{11} \mathrm{~N}+{ }_{-1}^{0} e$

Question 10

Complete the following nuclear reaction. ${ }_{98}^{249} \mathrm{Cf}+{ }_{6}^{12} \mathrm{C} \rightarrow 4_{0}^{1} n$

A) ${ }_{92}^{237} \mathrm{U}$
B) ${ }_{92}^{241} \mathrm{U}$
C) ${ }_{98}^{254} \mathrm{Cf}$
D) ${ }_{104}^{257} \mathrm{Cf}$
E) ${ }_{104}^{261} \mathrm{Rf}$

Question 11

A plot of the number of neutrons versus the number of protons in nuclei shows a narrow band of stable isotopes.By what method(s)can isotopes with a low proton-neutron ratio (i.e. ,ones that fall below the band of stability)decay to form elements that are more stable?

A) positron emission or electron capture.
B) positron emission or neutron capture.
C) beta emission or electron capture.
D) gamma ray emission or beta emission.
E) neutron capture or alpha emission.

Question 12

All of the following statements are true EXCEPT

A) gamma emission can accompany nuclear decay,such as beta emission.
B) gamma rays can be used to extend the shelf life of food products.
C) gamma rays have the same properties as electrons.
D) gamma emission consists of high energy photons.
E) gamma rays move at the speed of light.

Question 13

If a nucleus captures an electron,its atomic number

A) decreases by 2.
B) decreases by 1.
C) remains the same.
D) increases by 1.
E) increases by 2.

Question 14

What element is produced by the alpha decay of ${ }_{83}^{210} \mathrm{Bi}$ ?

A) ${ }_{81}^{210} \mathrm{Tl}$
B) ${ }_{9}^{8} \mathrm{Au}$
C) ${ }_{81}^{206} \mathrm{Tl}$
D) ${ }_{81}^{206} \mathrm{Bi}$
E) ${ }_{78}^{204} \mathrm{Pt}$

Question 15

If a nucleus emits an alpha particle,its mass number

A) decreases by 4.
B) decreases by 2.
C) remains the same.
D) increases by 1.
E) decreases by 2..

Question 16

Complete the following nuclear decay reaction. ${ }_{88}^{221} \mathrm{Ra} \rightarrow+{ }_{2}^{4} \mathrm{He}$

A) ${ }_{86}^{217} \mathrm{Rn}$
B) ${ }_{88}^{217} \mathrm{Ra}$
C) ${ }_{92}^{217} \mathrm{U}$
D) ${ }_{86}^{225} \mathrm{Rn}$
E) ${ }_{90}^{225} \mathrm{Th}$

Question 17

What nucleus decays by successive ?,?,? emissions to produce uranium-236?

A) ${ }_{88}^{232} \mathrm{Ra}$
B) ${ }_{88}^{230} \mathrm{Ra}$
C) ${ }_{92}^{240} \mathrm{Pu}$
D) ${ }_{94}^{242} \mathrm{Pu}$
E) ${ }_{92}^{940} \mathrm{~L}$

Question 18

Which of the following reactions is an example of positron emission?

A) ${ }_{91}^{227} \mathrm{~Pa} \rightarrow{ }_{89}^{223} \mathrm{Ac}+{ }_{2}^{4} \mathrm{He}$
B) ${ }_{20}^{41} \mathrm{Ca}+{ }_{-1}^{0} e \rightarrow{ }_{19}^{41} \mathrm{~K}$
C) ${ }_{79}^{201} \mathrm{Au} \rightarrow{ }_{80}^{201} \mathrm{Hg}+{ }_{-1}^{0} \mathrm{\beta}$
D) ${ }_{63}^{150} \mathrm{Eu} \rightarrow{ }_{62}^{150} \mathrm{Sm}+{ }_{+1}^{0} \beta$
E) ${ }_{26}^{58} \mathrm{Fe}+{ }_{0}^{1} n \rightarrow{ }_{26}^{59} \mathrm{Fe}$

Question 19

What nucleus decays by beta emission to produce antimony-121?

A) ${ }_{50}^{120} \mathrm{Sn}$
B) ${ }_{51}^{122} \mathrm{Sb}$
C) ${ }_{50}^{121} \mathrm{Sn}$
D) ${ }_{52}^{121} \mathrm{Te}$
E) ${ }_{53}^{125} \mathrm{D}$

Question 20

Which of the following reactions is an example of K-electron capture?

A) ${ }_{73}^{183} \mathrm{Ta} \rightarrow{ }_{74}^{183} \mathrm{~W}+{ }_{-1}^{0} e$
B) ${ }_{20}^{41} \mathrm{Ca}+{ }_{-1}^{0} e \rightarrow{ }_{19}^{41} \mathrm{~K}$
C) ${ }_{26}^{58} \mathrm{Fe}+{ }_{0}^{1} n \rightarrow{ }_{26}^{59} \mathrm{Fe}$
D) ${ }_{84}^{197} \mathrm{Po} \rightarrow{ }_{82}^{193} \mathrm{~Pb}+{ }_{2}^{4} \mathrm{He}$
E) ${ }_{3}^{7} \mathrm{Li}+{ }_{1}^{1} p \rightarrow 2{ }_{2}^{4} \mathrm{He}$

Question 21

The half-life of americium-241 is 457 years.What is the activity in curies of a 0.010 g sample of Am-241? (1 Ci = 3.700 × 10¹⁰ atom/s)

A) 0.032 Ci
B) 1.0 Ci
C) 1.0 × 10⁶ Ci
D) 1.0 × 10⁹ Ci
E) 3.79 × 10¹⁶ Ci

Question 22

All of the following statements are true EXCEPT

A) a nucleus weighs less than the protons and neutrons from which it is composed.
B) the difference in mass between a nucleus and its individual protons and neutrons is called the mass defect.
C) the process in which a nucleus decomposes to form two or more lighter nuclei is called nuclear fission.
D) nuclear fission evolves more energy than ordinary chemical reactions,such as the combustion of gasoline.
E) nuclear fission evolves more energy than nuclear fusion.

Question 23

The following reaction is an example of ____.
${ }_{92}^{236} \mathrm{U} \rightarrow{ }_{39}^{96} \mathrm{Y}+{ }_{53}^{136} \mathrm{I}+4{ }_{0}^{1} n$

A) fusion
B) fission
C) gamma radiation emission
D) beta emission
E) neutron bombardment

Question 24

The energy change for a nuclear reaction can be calculated from which of the following equations?

A)
B) ΔE = hv
C) ΔE = cΔm²
D) ΔE = c²Δm
E)

Question 25

An extremely sensitive method has recently been developed for measuring concentrations in organic materials.What is this method?

A) acid titration
B) nuclear magnetic resonance
C) gas chromatography
D) atomic absorption spectrometry
E) mass spectrometry

Question 26

The half-life of is 9.5 × 10¹² s.How many atoms of are present in a sample with an activity of 3.9 × 10⁹ atoms/s?

A) 1.9 × 10−²³ atoms
B) 4.1 × 10−⁴ atoms
C) 2.4 × 10³ atoms
D) 9.1 × 10¹⁶ atoms
E) 5.3 × 10²² atoms

Question 27

A 1.00 g sample of carbon taken from a living plant has an activity of 13.6 atoms/min.If 1.00 g of an organic sample is found to have an activity of 6.27 atoms/min,what is the age of the sample? The decay constant of is 1.21 × 10−⁴ yr−¹.

A) 2.64 × 10³ yr
B) 5.28 × 10³ yr
C) 6.40 × 10³ yr
D) 8.18 × 10³ yr
E) 1.07 × 10⁴ yr

Question 28

A 1.00 g sample of carbon taken from a fossilized plant has an activity of 0.19 atoms/s.What mass of ${ }_{6}^{14} \mathrm{C}$ is present? The decay constant of ${ }_{6}^{14} \mathrm{C}$ is 3.8 × 10?¹² s?¹.

A) 4.6 × 10?³⁴ g
B) 5.0 × 10?¹⁴ g
C) 1.2 × 10?¹² g
D) 6.1 × 10?¹² g
E) 3.2 × 10?¹¹ g

Question 29

The point of maximum stability in the binding energy curve occurs in the vicinity of which one of the following isotopes?

A) ${ }_{2}^{4} \mathrm{He}$
B) ${ }_{26}^{56} \mathrm{Fe}$
C) ${ }_{5}^{11} \mathrm{B}$
D) ${ }_{83}^{209} \mathrm{Bi}$
E) ${ }_{91}^{231} \mathrm{Pa}$

Question 30

The following nuclear reaction is an example of ____.
$4_{1}^{1} \mathrm{H} \rightarrow{ }_{2}^{4} \mathrm{He}+2_{1}^{0} e$

A) fusion
B) fission
C) gamma radiation emission
D) beta emission
E) hydrogen combustion

Question 31

Carbon dating can be applied to organic materials up to 5.0 × 10⁴ years old.What percentage of the original is present in a sample after this much time? The half-life of is 5730 yr.

A) 0.0011%
B) 0.24%
C) 0.89%
D) 6.0%
E) 8.7%

Question 32

The half-life of mercury-203 is 46.6 days.What percentage of mercury-203 remains in a sample after 365 days?

A) 3.72 × 10−⁴ %
B) 0.439%
C) 1.49%
D) 5.43%
E) 12.8%

Question 33

How long does it take for 105 mg of tritium, ,to decay to 35.0 mg? The half-life of tritium is 12.3 yr.

A) 12.3 yr
B) 14.2 yr
C) 19.5 yr
D) 24.6 yr
E) 36.9 yr

Question 34

How many atoms decay in 12 hours in a 3.5 × 10−⁸ Ci source? (1 Ci = 3.700 × 10¹⁰ atom/s)

A) 4.1 × 10−¹⁴ atoms
B) 1.6 × 10⁴ atoms
C) 5.0 × 10⁴ atoms
D) 5.6 × 10⁷ atoms
E) 4.6 × 10²² atoms

Question 35

The rate constant for the decay of copper-62 is 9.8 minutes−¹.What is the half-life of this isotope?

A) 0.071 m.
B) 1.6 m.
C) 14 m.
D) 0.10 m.
E) 9.8 m.

Question 36

What is the relationship between the rate constant and the half-life for nuclear decay?

A) rate = kt_1/2
B)
C) k = ln (0.693t_1/2)
D)
E) k = 0.693t_1/2

Question 37

The decay constant,k,for is 1.37 × 10−¹¹ s−¹.What mass of has an activity of 1.06 × 10⁹ atoms/s?

A) 6.60 × 10−⁶ g
B) 1.49 × 10−³ g
C) 2.90 × 10−² g
D) 3.44 × 10¹ g
E) 8.97 × 10² g

Question 38

Uranium-235 has a half-life of 7.04 × 10⁸ years.How many years will it take for 99.9% of a U-235 sample to decay?

A) 7.0 × 10⁵ yr
B) 1.0 × 10⁶ yr
C) 4.7 × 10⁹ yr
D) 4.9 × 10⁹ yr
E) 7.0 × 10⁹ yr

Question 39

A 1.00 g sample of decays to 0.87 g in 1.9 hr.What is the half-life of ?

A) 0.073 hr
B) 0.11 hr
C) 4.5 hr
D) 9.5 hr
E) 14 hr

Question 40

All of the following statements concerning radiocarbon dating are true EXCEPT

A) radiocarbon dating is used to determine the age of meteorites.
B) the decay of is used for radiocarbon dating.
C) radioactive carbon is produced by the reaction of cosmic radiation and nitrogen-14.
D) radioactive carbon decays into a nitrogen-14 atom and a beta particle.
E) radiocarbon dating is limited to objects less than 50,000 years old.

Question 41

Human exposure to radiation comes primarily from

A) medical x-rays.
B) sitting too close to the television.
C) nuclear fallout from bomb tests.
D) radon gas.
E) using cellular telephones.

Question 42

All of the following statements are true EXCEPT

A) for a nuclear fission chain reaction to occur,one neutron must be produced for each one consumed.
B) in a light water nuclear reactor,steam drives the turbines used to generate electricity.
C) in a fission reactor, ${ }_{92}^{235} \mathrm{U}$ reacts with a neutron to produce more neutrons and products of lower mass.
D) many of the fission products of ${ }_{92}^{235} \mathrm{U}$ are radioactive.
E) one function of the water in a light water reactor is to slow down neutrons given off by fission.

Question 43

Calculate the energy change per mole for the following reaction? ${ }_{1}^{2} \mathrm{H}+{ }_{1}^{2} \mathrm{H} \rightarrow{ }_{2}^{4} \mathrm{He}$ The mass of ${ }_{1}^{2} \mathrm{H}$ is 2.01355 amu and the mass of ${ }_{2}^{4} \mathrm{He}$ is 4.00150 amu.

A) 2.30 × 10⁹ kJ/mol
B) 9.00 × 10⁹ kJ/mol
C) 1.79 × 10¹¹ kJ/mol
D) 3.52 × 10¹² kJ/mol
E) 2.84 × 10¹³ kJ/mol

Question 44

The molar nuclear mass of fluorine-19 is 18.99840 g/mol.The molar mass of a proton is 1.007825 g/mol.The molar mass of a neutron is 1.008665 g/mol.Calculate the binding energy (in kJ/mol)of F-19.(c = 2.998 × 10⁸ m/s)

A) 6.753 × 10⁹ kJ/mol
B) 7.131 × 10⁹ kJ/mol
C) 1.426 × 10¹⁰ kJ/mol
D) 8.609 × 10¹¹ kJ/mol
E) 8.538 × 10¹¹ kJ/mol

Question 45

Marie Curie was the first person in history to

A) discover radioactivity.
B) die from leukemia.
C) win two Nobel Prizes.
D) name an element.
E) discover the neutron.

Question 46

Most of the nuclear power on earth is produced primarily from

A) nuclear fission of ²³⁵U.
B) nuclear fusion of ²³⁵U.
C) nuclear fission of ¹H.
D) nuclear fusion of ¹H.
E) nuclear fusion of ²H.

Question 47

All of the following statements are true EXCEPT

A) the Sun's energy comes primarily from the fusion of hydrogen.
B) fusion reactions have high activation barriers due to repulsion of nuclei.
C) fission reactions have relatively low activation barriers because uncharged neutrons used to initiate the reactions are not repelled by nuclei.
D) magnetic fields can be used to confine nuclei during a fusion reaction.
E) many fission reactors have been replaced by fusion reactors,which produce more energy and fewer waste products.

Question 48

Radioactive elements have been used

A) to determine the age of artifacts.
B) to treat food to reduce spoilage.
C) in smoke detectors.
D) both a and b
E) all of the above

Question 49

The following fusion reaction releases 2.16 × 10⁹ kJ per mole of deuterium reacted. ${ }_{1}^{2} \mathrm{H}+{ }_{3}^{6} \mathrm{Li} \rightarrow 2{ }_{2}^{4} \mathrm{He}$ How much mass is lost in the reaction per mole of deuterium reacted?

A) 1.2 × 10?⁵ g
B) 2.4 × 10?⁵ g
C) 1.2 × 10?² g
D) 2.4 × 10?² g
E) 1.2 × 10?¹ g

Question 50

Calculate the energy released (per mole of deuterium consumed)for the following fusion reaction, ${ }_{1}^{2} \mathrm{H}+{ }_{1}^{3} \mathrm{H} \rightarrow{ }_{2}^{4} \mathrm{He}+{ }_{0}^{1} n$ given the following molar masses of nucleons and nuclei.
(c = 2.998 × 10⁸ m/s) particle
$\begin{array}{ll}\text { particle } & \text { mass }(\mathrm{g} / \mathrm{mol}) \\\hline \text { proton } & 1.007825 \\\text { neutron } & 1.008665 \\\text { deuterium } & 2.0140 \\\text { tritium } & 3.01605 \\\text { helium-4 } & 4.00260\end{array}$

A) 5.63 × 10³ kJ/mol
B) 1.69 × 10¹² kJ/mol
C) 4.62 × 10¹⁰ kJ/mol
D) 8.44 × 10⁸ kJ/mol
E) 1.69 × 10⁹ kJ/mol

Question 51

Most of the sun's energy is produced primarily from

A) nuclear fission of ²³⁵U.
B) nuclear fusion of ²³⁵U.
C) nuclear fission of ¹H.
D) nuclear fusion of ¹H.
E) nuclear fusion of ²H.