Deck 23: Nuclear Reactions and Their Applications

Question 1

An isotope with a low value of N/Z will generally decay through

A)( $\alpha$ decay.)
B)9 $\beta$ decay.)
C)( $\gamma$ decay.)
D)electron capture.
E)spontaneous fission.

Answer 1

electron capture.

Question 2

Select the nuclide that completes the following nuclear reaction.

A)

B)

C)

D)

E)

Answer 2

Question 3

Select the nuclide that completes the following nuclear reaction.

A)

B)

C)

D)

E)None of these choices is correct.

Answer 3

Question 4

The radioisotope
Will decay through

A)( $\alpha$ decay.)
B)( $\beta$ decay.)
C)( $\gamma$ decay.)
D)electron capture.
E)spontaneous fission.

Question 5

An isotope with a high value of N/Z will tend to decay through

A)( $\alpha$ decay.)
B)( $\beta$ decay.)
C)positron decay.
D)electron capture.
E)( $\gamma$ decay.)

Question 6

The radioisotope
Will decay through

A)( $\alpha$ decay.)
B)9 $\beta$ decay.)
C)( $\gamma$ decay.)
D)positron decay.
E)electron capture.

Question 7

Which one of the following equations correctly represents positron decay of
?

A)

B)

C)

D)

E)

Question 8

Select the nuclide that completes the following nuclear reaction.

A)

B)

C)

D)

E)

Question 9

Select the nuclide that completes the following nuclear reaction.

A)

B)

C)

D)

E)

Question 10

The isotopes
And
Are all stable,while
Is radioactive.The mode of decay for
Is most likely to be

A)positron decay.
B)alpha decay.
C)beta decay.
D)gamma decay.
E)fission.

Question 11

Select the nuclide that completes the following nuclear reaction.

A)

B)

C)

D)

E)

Question 12

An isotope with Z > 83,which lies close to the band of stability,will generally decay through

A)( $\alpha$ decay.)
B)( $\beta$ decay.)
C)( $\gamma$ decay.)
D)positron decay.
E)electron capture.

Question 13

Which one of the following equations correctly represents electron capture by the
Nucleus?

A)

B)

C)

D)

E)

Question 14

The isotopes
Are all stable,while
Is radioactive.The mode of decay for
Is most likely to be

A)positron decay.
B)( $\alpha$ decay.)
C)( $\gamma$ decay.)
D)electron capture.
E)( $\beta$ decay.)

Question 15

Select the nuclide that completes the following nuclear reaction.

A)

B)

C)

D)

E)

Question 16

Select the nuclide that completes the following nuclear reaction.

A)

B)

C)

D)

E)None of these choices is correct.

Question 17

Which one of the following is an incorrect representation of the indicated particle or nucleus?

A)

B)

C)

D)

E)

Question 18

Select the nuclide that completes the following nuclear reaction.

A)

B)

C)

D)

E)

Question 19

Which one of the following equations correctly represents alpha decay of
?

A)

B)

C)

D)

E)

Question 20

The radioisotope
Will decay through

A)( $\alpha$ decay.)
B)( $\beta$ decay.)
C)positron decay.
D)electron capture.
E)( $\gamma$ decay.)

Question 21

The isotope
Has a half-life of 21 hours.If a sample initially contains exactly 10000 atoms of
,approximately how many of these atoms will remain after one week?

A)1250
B)78
C)39
D)0
E)None of these choices is correct.

Question 22

Which of the following isotopes is most likely to be unstable?

A)

B)

C)

D)

E)

Question 23

Identify the missing species in the following nuclear transmutation.

A)

B)

C)

D)

E)

Question 24

Palladium-107 undergoes $\beta$ decay (t_1/2 = 6.5 $\times$ 10⁵ yr)to form silver-107.How long will it take for 0.150 mol of silver-107 to form from 1.25 mol of palladium-107?

A)2.0 $\times$ 10⁷ y
B)1.4 $\times$ 10⁷ y
C)1.2 $\times$ 10⁶ y
D)8.3 $\times$ 10⁵ y
E)1.2 $\times$ 10⁵ y

Question 25

The isotopes of promethium,
And
,are unstable,and lie on opposite sides of the "line of stability".Which of the following combinations is most likely to represent the type of decay for these isotopes?

A)promethium-144, $\beta$ decay;promethium-134,positron decay
B)promethium-144,positron decay;promethium-134, $\beta$ decay
C)promethium-144,positron decay;promethium-134,electron capture
D)promethium-144,electron capture;promethium-134,positron decay
E)promethium-144, $\beta$ decay;promethium-134, $\gamma$ decay

Question 26

Which of the following isotopes is most likely to be unstable?

A)

B)

C)

D)

E)

Question 27

What is the specific activity (in Ci/g)of an isotope if 3.56 mg emits 4.26 $\times$ 10⁸ $\beta$ particles per second?

A)0.003232 Ci/g
B)0.0115 Ci/g
C)0.309 Ci/g
D)3.23 Ci/g
E)None of these choices is correct.

Question 28

Cesium-134 is a $\beta$ emitter with a half-life of 2.0 years.How much of a 2.50-g sample of cesium-134 will remain after 10 years?

A)0.0024 g
B)0.078 g
C)0.25 g
D)0.50 g
E)None of these choices is correct.

Question 29

Which of the following isotopes is most likely to be unstable?

A)

B)

C)

D)

E)

Question 30

The isotope
Is unstable.This is predictable because

A)N/Z $\neq$ 1.
B)N/Z is relatively low and Z < 20.
C)N/Z is relatively large and Z < 20.
D)Z is small.
E)N is large.

Question 31

A pure sample of tritium,³H,was prepared and sealed in a container for a number of years.Tritium undergoes $\beta$ decay with a half-life of 12.32 years.How long has the container been sealed if analysis of the contents shows there are 5.25 mol of ³H and 6.35 mol of ³He present?

A)2.34 y
B)3.38 y
C)9.77 y
D)14.1 y
E)25.6 y

Question 32

A 7.85 $\times$ 10^-5 mol sample of copper-61 emits 1.47 $\times$ 10¹⁹ positrons in 90.0 minutes.What is the decay constant for copper-61?

A)0.00230 h^-1
B)0.00346 h^-1
C)0.207 h^-1
D)0.311 h^-1
E)None of these choices is correct.

Question 33

Which of the following isotopes is definitely unstable?

A)

B)

C)

D)

E)

Question 34

Identify the missing species in the following nuclear transmutation.

A)2

B)3

C)

D)

E)

Question 35

A 9.52 $\times$ 10^-5 mol sample of rubidium-86 emits 8.87 $\times$ 10¹⁶ $\beta$ particles in one hour.What is the half-life of rubidium-86?

A)2.23 $\times$ 10^-3 h
B)1.55 $\times$ 10^-3 h
C)448 h
D)645 h
E)None of these choices is correct.

Question 36

The isotope
Is unstable.This is predictable because

A)the number of neutrons is too large in relation to the number of protons.
B)the number of neutrons is too small in relation to the number of protons.
C)the atomic number is too large.
D)the mass number is too large.
E)Sc isotopes are all unstable.

Question 37

Iodine-131,t_1/2 = 8.0 days,is used in diagnosis and treatment of thyroid gland diseases.If a laboratory sample of iodine-131 initially emits 9.95 $\times$ 10¹⁸ $\beta$ particles per day,how long will it take for the activity to drop to 6.22 $\times$ 10¹⁷ $\beta$ particles per day?

A)2.0 days
B)16 days
C)32 days
D)128 days
E)None of these choices is correct.

Question 38

A certain isotope has a specific activity of 7.29 $\times$ 10^-4 Ci/g.How many $\alpha$ particles will a 75.0 mg sample emit in one hour?

A)9.99 $\times$ 10⁴
B)2.02 $\times$ 10⁶
C)7.28 $\times$ 10⁹
D)1.29 $\times$ 10¹²
E)None of these choices is correct.

Question 39

The isotope
Has a half-life of 7.5 seconds.If a sample contains 144 atoms of
,approximately how many such atoms were there present 30 seconds earlier?

A)576
B)1152
C)2304
D)4320
E)4.30 $\times$ 10⁸

Question 40

The radiochemist,Will I.Glow,studied thorium-232 and found that 2.82 $\times$ 10^-7 moles emitted 8.42 $\times$ 10⁶ $\alpha$ particles in one year.What is the decay constant for thorium-232?

A)3.35 $\times$ 10^-14 yr^-1
B)4.96 $\times$ 10^-11 yr^-1
C)1.40 $\times$ 10¹⁰ yr^-1
D)2.99 $\times$ 10¹³ yr^-1
E)None of these choices is correct.

Question 41

Write a complete,balanced equation to represent the electron capture decay of argon-37.

Question 42

Write a complete,balanced equation to represent the formation of manganese-55 by the beta decay of another nuclide.

Question 43

Fill in missing sub- and superscripts for all particles to complete the following equation for beta decay.

Question 44

Calcium-39 undergoes positron decay.Each positron carries 5.49 MeV of energy.How much energy will be emitted when 0.0025 mol of calcium-39 decays?

A)13.2 kJ
B)1.32 $\times$ 10⁴ kJ
C)1.32 $\times$ 10⁶ kJ
D)1.32 $\times$ 10⁹ kJ
E)None of these choices is correct.

Question 45

Exposure to 10 nCi for 10 minutes is more hazardous for a child than for an adult because

A)the child's cells are dividing more rapidly than the adult's and are,therefore,more susceptible to the radiation.
B)the child's smaller body size makes the effective dose larger for the child than for the adult.
C)the child's immune system is not developed well enough to resist damage.
D)the child's skin is not as thick as an adult's and cannot block as much radiation.
E)None of these reasons is correct.

Question 46

Write a complete,balanced equation to represent the alpha decay of radon-210.

Question 47

Sodium-21 will emit positrons each having an energy of 4.0 $\times$ 10^-13 J.What is this energy in MeV?

A)4.0 $\times$ 10^-7 MeV
B)2.5 MeV
C)40 MeV
D)2.5 $\times$ 10⁶ MeV
E)None of these choices is correct.

Question 48

Explain how the number of protons and neutrons in a radioactive nucleus can be used to predict its probable mode of decay.Illustrate your answer with a schematic graph,properly labeled,showing stable nuclides (nuclei)in relation to number of protons and neutrons.

Question 49

An 85-kg person exposed to barium-141 receives 2.5 $\times$ 10⁵ $\beta$ particles,each with an energy of 5.2 $\times$ 10^-13 J.How many rads does the person receive?

A)2.4 $\times$ 10^-20
B)1.5 $\times$ 10^-7
C)1.8 $\times$ 10^-16
D)6.1 $\times$ 10^-15
E)None of these choices is correct.

Question 50

Fill in missing sub- and superscripts for all particles to complete the following equation for positron decay.

Question 51

It is believed that two carbon-12 nuclei can react in the core of a supergiant star to form sodium-23 and hydrogen-1.Calculate the energy released from this reaction for each mole of hydrogen formed.The masses of carbon-12,sodium-23,and hydrogen-1 are 12.0000 amu,22.989767 amu,and 1.007825,respectively.

A)2.16 $\times$ 10¹⁴ kJ
B)2.16 $\times$ 10¹¹ kJ
C)2.16 $\times$ 10⁸ kJ
D)2.16 $\times$ 10⁵ kJ
E)None of these choices is correct.

Question 52

Identify the missing species in the following nuclear transmutation.

A)

B)

C)

D)

E)

Question 53

Which of the following materials is put into a nuclear reactor to slow the chain reaction?

A)heavy water
B)moderators
C)control rods
D)reflectors
E)chlorine

Question 54

Carbon-14 will emit a $\beta$ particle with an energy of 0.1565 MeV.What is this energy in joules?

A)1.0 $\times$ 10^-24 J
B)2.5 $\times$ 10^-20 J
C)1.0 $\times$ 10^-18 J
D)2.5 $\times$ 10^-14 J
E)None of these choices is correct.

Question 55

A patient's thyroid gland is to be exposed to an average of 5.5 µCi for 16 days as an ingested sample of iodine-131 decays.If the energy of the $\beta$ radiation is 9.7 $\times$ 10^-14 J and the mass of the thyroid is 32.0 g,what is the dose received by the patient?

A)0.027 rads
B)1.2 rads
C)37 rads
D)85 rads
E)None of these choices is correct.

Question 56

Identify the missing species in the following nuclear transmutation.

A)

B)

C)

D)

E)None of these choices is correct.

Question 57

A 30.0-kg child receives 2.65 $\times$ 10⁷ $\beta$ particles,each with an energy of 4.60 $\times$ 0 10^-13 J.If the RBE = 0.78,how many millirem did the child receive?

A)3.2 $\times$ 10^-7
B)5.2 $\times$ 10^-7
C)5.2 $\times$ 10^-4
D)3.2 $\times$ 10^-2
E)None of these choices is correct.

Question 58

A 55-kg person exposed to thorium-234 receives 7.5 $\times$ 10⁴ $\beta$ particles,each with an energy of 1.6 $\times$ 10^-14 J.How many rads does the person receive?

A)2.1 $\times$ 10^-19
B)1.2 $\times$ 10^-17
C)2.2 $\times$ 10^-9
D)1.2 $\times$ 10^-9
E)None of these choices is correct.

Question 59

Fill in missing sub- and superscripts for all particles to complete the following equation for alpha decay.

Question 60

Write a complete,balanced equation to represent the beta decay of thallium-207.

Question 61

Calculate to four significant figures
a.the mass defect in kg and
b.the energy released in kJ/mol,when a neutron decays to produce a proton and an electron.The neutron,proton and electron masses are 1.67493 $\times$ 10^-27 kg,1.67262 $\times$ 10^-27 kg and 9.10939 $\times$ 10^-31 kg,respectively.

Question 62

After 4 half-lives,the fraction of a radioactive isotope which still remains is approximately one eighth.

Question 63

No alpha decay is observed for isotopes of elements with Z < 83.

Question 64

The masses of a potassium-40 atom,a proton and a neutron are 39.963999 amu,1.007825 amu and 1.008665 amu,respectively.Calculate to four significant figures
a.the mass defect in amu and
b.the energy released in MeV/nucleon,in the formation of
from the appropriate number of protons and neutrons.

Question 65

When an electron and its anti-particle,a positron,collide,they annihilate each other.Calculate the energy released in this process,in J.(The positron mass is the same as the electron mass,namely 9.11 $\times$ 10^-31 kg. )

Question 66

Radioactive decay follows zero-order kinetics.

Question 67

Most foodstuffs contain natural,radioactive isotopes.

Question 68

The binding energy per nucleon reaches a maximum for the isotope
.

Question 69

Bombardment of uranium-238 nuclei by carbon-12 nuclei produces californium-246 and neutrons.Write a complete,balanced equation for this nuclear process.

Question 70

A bottle of vintage red wine has lost its label.The concentration of tritium (
)in the wine is 0.34 times that found in freshly bottled wines.If the half-life of tritium is 12.3 years,estimate the time elapsed since the wine was bottled.

Question 71

Gamma rays are not deflected by an electric field.

Question 72

Gamma rays are high energy electrons.

Question 73

Briefly explain the relationship between the rad and the rem as units of radiation dosage.

Question 74

What is the mechanism by which control rods slow down the fission rate in a nuclear reactor?

Question 75

Positron decay and electron capture have the same net effect on the Z and N values of a nucleus.