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American System Physics

A Physics Toolkit

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Representing Motion

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Accelerated Motion

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Forces in One Dimension

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Displacement and Force in Two Dimensions

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Motion in Two Dimensions

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Gravitation

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Rotational Motion

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Momentum and Its Conservation

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Energy and Its Conservation

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Thermal Energy

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States of Matter

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Vibrations and Waves

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Sound

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Fundamentals of Light

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Reflection and Refraction

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Interference and Diffraction

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Electrostatics

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Electric Current and Circuits

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Magnetic Fields

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Electromagnetic Induction and Electromagnetism

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Quantum Theory and the Atom

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Solid-State Electronics

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Nuclear and Particle Physics

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Quiz

24.2 Nuclear Decay and Reactions – Quiz

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Nuclear Decay and Reactions American Physics quiz: free practice for American System Physics. Work through this Nuclear Decay and Reactions American Physics quiz and get instant feedback on every answer. If you get stuck, review the 24.2 Nuclear Decay and Reactions — Notes lesson. More practice: American System Physics — all units. Syllabus: OpenStax free science textbooks.

  • Questions count: 50
  • Passing grade: A-
  • Time limit:
Start Quiz
1.
Using the decay graph, what is the half-life of the source?
Dr Dabour Hub Academy - figure 1
8 min
2 min
16 min
4 min
2.
The graph shows the measured count rate, which includes a background of 60 counts per minute. What is the half-life of the source?
Dr Dabour Hub Academy - figure 2
About 37 s
30 s
15 s
60 s
3.
Using the graph, estimate the activity of the source after 10.6 years.
Dr Dabour Hub Academy - figure 3
500 Bq
125 Bq
100 Bq
250 Bq
4.
The graph shows corrected count rate as aluminium sheets are added between a source and a detector. The count rate is almost unaffected by paper. Which radiation is mainly detected?
Dr Dabour Hub Academy - figure 4
Beta
Alpha
Gamma only
Neutrons
5.
The diagram shows three types of radiation entering a uniform field. Which track is gamma radiation?
Dr Dabour Hub Academy - figure 5
Track 1
Track 2
Track 3
None of them
6.
The background is 25 counts per minute. What does the table show about the source?
It emits gamma only
It emits alpha only
It emits all three
It emits alpha and beta but no gamma
7.
Why is the reading with 5 cm of lead in the table not zero?
Background radiation is always present
Lead is radioactive
Alpha particles pass through lead
The counter is broken
8.
From the tabulated rates, once background is removed, how often does the activity halve?
4 min
2 min
1 min
3 min
9.
Which source in the table is most suitable as a medical tracer injected into a patient?
Q
R
None
P
10.
Which source in the table would be most dangerous if swallowed?
R
P
Q
All equally
11.
Using the table, which pairing is correct?
Process Y - fusion
Process X - fusion
Process X - fission
Process Y - needs 108 K
12.
Using the table, what is the mean background count rate?
25 counts per minute
100 counts per minute
20 counts per minute
9 counts per minute
13.
Which statement best describes radioactive decay?
It is random and spontaneous and is unaffected by temperature or pressure
It speeds up when the source is heated
It can be stopped by chemical reactions
It happens at predictable times for each nucleus
14.
What is an alpha particle?
A fast electron
Two protons and two neutrons (a helium-4 nucleus)
A high-energy photon
A single neutron
15.
A safety officer is choosing shielding. Which radiation is matched with a material that stops it?
Alpha - thick lead
Gamma - a sheet of paper
Beta - a few cm of air only
Beta - a few mm of aluminium
16.
Damage to living cells depends on ionisation. Which radiation is correctly described by how strongly it ionises?
Alpha - strongly ionising
Gamma - strongly ionising
Beta - not ionising
Alpha - weakly ionising
17.
Each nuclear energy process needs special conditions. Which process is matched with its requirement?
Fission - very high temperature only
Fusion - extremely high temperature and pressure
Fusion - slow neutrons and critical mass
Fission - joining light nuclei
18.
Which pairing of decay and change to the nucleus is correct?
Beta-minus - A decreases by 1
Gamma - Z increases by 1
Alpha - A decreases by 4, Z decreases by 2
Alpha - Z increases by 2
19.
What is a chain reaction?
A series of alpha decays in a rock
Fusion of hydrogen in the Sun
The decay of a nucleus into a chain of gamma rays
A self-sustaining series of fissions in which released neutrons cause further fissions
20.
Why does fusion require extremely high temperatures?
Nuclei need huge kinetic energies to overcome electrostatic repulsion
Neutrons must be slowed down
The nuclei must be melted
To create critical mass
21.
Radium-226 (Z = 88) emits an alpha particle to form radon. What are the nucleon and proton numbers of the radon nucleus?
A = 224, Z = 84
A = 226, Z = 89
A = 222, Z = 86
A = 222, Z = 90
22.
Carbon-14 (Z = 6), used in dating, undergoes beta-minus decay. Which nucleus is formed?
A = 14, Z = 7 (nitrogen-14)
A = 14, Z = 5 (boron-14)
A = 13, Z = 7
A = 10, Z = 4
23.
U-238 (Z = 92) decays to Pb-206 (Z = 82) by a series of alpha and beta-minus decays. How many alpha decays occur?
6
10
32
8
24.
For the decay chain U-238 (Z = 92) to Pb-206 (Z = 82), how many beta-minus decays occur?
6
8
10
2
25.
An 80 g sample of an isotope has a half-life of 3 days. What mass of the isotope remains after 12 days?
20 g
40 g
5 g
10 g
26.
A source has an activity of 6400 Bq and a half-life of 8.0 hours. How long until its activity is 400 Bq?
32 hours
16 hours
4 hours
128 hours
27.
What fraction of a radioactive sample remains undecayed after 5 half-lives?
1/5
1/32
1/10
1/25
28.
A sample's activity falls from 1200 Bq to 150 Bq in 36 minutes. What is the half-life?
4.5 minutes
18 minutes
12 minutes
36 minutes
29.
In one minute, 3.0e+20 nuclei in a sample decay. What is the average activity?
3.0e+20 Bq
1.8e+22 Bq
8.3e+16 Bq
5.0e+18 Bq
30.
In a fission reaction the total mass decreases by 0.186 u. How much energy is released?
173 MeV
0.186 MeV
2.78e-11 MeV
5008 MeV
31.
In the fusion 2H + 3H -> 4He + n the mass decreases by 0.0189 u. What energy is released?
17605 MeV
17.6 MeV
0.0189 MeV
3.52 MeV
32.
From the graph, the corrected count rate after 12 minutes is about _____.
Dr Dabour Hub Academy - figure 6
100 counts per minute
200 counts per minute
50 counts per minute
267 counts per minute
33.
The unit of activity, equal to one decay per second, is the _____.
sievert
becquerel
gray
hertz per second
34.
The minimum mass of fissile material needed for a self-sustaining chain reaction is the _____.
half-life
binding mass
critical mass
mass defect
35.
Strontium-90 (Z = 38) is a beta-minus emitter; its daughter nucleus has proton number _____.
37
39
38
36
36.
In the fission reaction n + U-235 (Z = 92) -> Ba-141 (Z = 56) + Kr-92 (Z = 36) + x neutrons, balancing nucleon numbers gives x = _____.
2
1
3
4
37.
Th-234 (Z = 90) decays to Pa-234 (Z = 91). The particle emitted is a(n) _____.
alpha particle
beta-minus particle
gamma ray
neutron
38.
A Geiger counter records 540 counts per minute near a source; background is 30 counts per minute. The corrected count rate is _____.
570 counts per minute
540 counts per minute
510 counts per minute
18 counts per minute
39.
For the graph shown, reading the time for 660 to fall to 330 counts per minute would give the correct half-life. True or false?
Dr Dabour Hub Academy - figure 7
True
True only after 150 s
False, because the background must be subtracted first
False, because half-life cannot be found from a graph
40.
In the diagram, tracks 1 and 3 curve in opposite directions because the particles have opposite charges. True or false?
Dr Dabour Hub Academy - figure 8
False, because they have the same charge
False, because they have different speeds only
True
True only for gamma
41.
Using the table, the corrected count rate at 8 minutes would be about 45 counts per minute. True or false?
False, about 90
False, about 65
True
True only if background is ignored
42.
The variation between readings in the table shows that radioactive emission is random. True or false?
False, it shows the counter is faulty
False, it shows the half-life is changing
True only for alpha sources
True
43.
The table shows an isotope with a half-life of 15 hours. True or false?
True
False, it is 30 hours
False, it is 7.5 hours
True only for the first reading
44.
Using the table, after 60 hours about 4 mg of the isotope would remain. True or false?
False, 0 mg
True
False, 2 mg
True only if temperature is constant
45.
Gamma rays have no charge and no mass. True or false?
False, they carry charge -1
False, they have a mass of 4 u
True
True only in magnetic fields
46.
In beta-minus decay a neutron in the nucleus changes into a proton. True or false?
False, a proton changes into a neutron
False, the nucleus loses two protons
True only for alpha emitters
True
47.
Gamma emission changes the proton number of a nucleus. True or false?
False, because gamma emission changes neither A nor Z
True
True only for heavy nuclei
False, because it changes A only
48.
Background radiation comes partly from natural sources such as radon gas and cosmic rays. True or false?
False, it comes only from nuclear power
True
False, it is caused by the Geiger counter
True only indoors
49.
When polonium-210 (Z = 84) decays by alpha emission, the lead nucleus formed has 124 neutrons. True or false?
False, it has 126
False, it has 82
True only if gamma is also emitted
True
50.
A hospital receives 200 mg of a tracer with a 5-day half-life; 15 days later 25 mg of it is left. True or false?
False, 66.7 mg is left
False, 50 mg is left
True only if it is kept cold
True
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Part of Nuclear and Particle Physics — see every lesson and quiz in this unit.
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