8) The missing product from this reaction is __________.
121
53
I →
121
52
Te + _____
A)
4
2
He
B)
0
-1
e
C)
1
0
n
D)
0
1
e
E)
0
0
γ
9) The missing product from this reaction is __________.
37
17
Cl + _____ →
38
18
Ar +
0
-1
e
A)
4
2
He
B)
0
-1
e
C)
1
0
n
D)
0
1
e
E)
0
0
γ
10) The missing product from this reaction is __________.
27
13
Al +
1
0
n →
28
14
Si + _____
A)
4
2
He
B)
0
-1
e
C)
1
0
n
D)
0
1
e
E)
0
0
γ
11) The missing product from this reaction is __________.
10
5
B + _____ →
13
7
N +
1
0
n
A)
4
2
He
B)
0
-1
e
C)
1
0
n
D)
0
1
e
E)
0
0
γ
12) The missing product from this reaction is __________.
221
87
Fr →
217
85
N + _____
A)
4
2
He
B)
0
-1
e
C)
1
0
n
D)
0
1
e
E)
0
0
γ
13) The missing product from this reaction is __________.
122
53
I → _____ +
0
-1
e
A)
122
52
Te
B)
122
54
Xe
C)
121
52
Te
D)
0
1
e
E) none of the above
14) The missing product from this reaction is __________.
19
11
Na → _____ +
0
1
e
A)
18
11
Na
B)
18
12
Mg
C)
19
12
Mg
D)
18
10
Ne
E) none of the above
15) The missing product from this reaction is __________.
75
34
Se +
0
-1
e → _____
A)
74
34
Se
B)
75
33
As
C)
75
34
Se
D)
75
35
Br
E) none of the above
16) The missing product from this reaction is __________.
227
93
Np →
223
91
Pa + _____
A)
4
2
He
B)
0
-1
e
C)
1
0
n
D)
0
1
e
E)
0
0
γ
17) This reaction is an example of __________.
41
20
Ca →
41
19
K + _____
A) alpha decay
B) beta decay
C) positron decay
D) electron capture
E) gamma emission
18) This reaction is an example of __________.
85
36
Kr →
85
37
Rb + _____
A) alpha decay
B) beta decay
C) positron decay
D) electron capture
E) gamma emission
19) This reaction is an example of __________.
30
15
P →
30
14
Si + _____
A) alpha decay
B) beta decay
C) positron decay
D) electron capture
E) gamma emission
20) This reaction is an example of __________.
30
15
P + _____ →
30
14
Si
A) alpha decay
B) beta decay
C) positron decay
D) electron capture
E) gamma emission
21) The missing product in this reaction would be found in which group of the periodic table?
24
11
Na →
0
-1
e + _____
A) 1A
B) 2A
C) 3A
D) 8A
E) 7A
22) The missing product in this reaction combines with oxygen to form a compound with the formula
__________.
42
19
K →
0
-1
e + _____
A) M2O
B) MO
C) MO2
D) M2O3
E) M2O2
23) Radium undergoes alpha decay. The product of this reaction also undergoes alpha decay. What is the
product of this second decay reaction?
A) Po
B) Rn
C) U
D) Th
E) Hg
24) 41Ca decays by electron capture. The product of this reaction undergoes alpha decay. What is the
product of this second decay reaction?
A) Ti
B) Ca
C) Ar
D) Cl
E) Sc
25) What is the mass number of a neutron?
A) 2
B) 1
C) 3
D) 4
E) 0
26) Nuclei above the belt of stability can lower their neutron-to-proton ratio by __________.
A) beta emission
B) gamma emission
C) positron emission
D) electron capture
E) Any of the above processes will lower the neutron-to-proton ratio.
27) What is the largest number of protons that can exist in a nucleus and still be stable?
A) 206
B) 50
C) 92
D) 83
E) 84
28) The three radioactive series that occur in nature end with what element?
A) Bi
B) U
C) Po
D) Pb
E) Hg
29) The largest number of stable nuclei have an __________ number of protons and an __________
number of neutrons.
A) even, even
B) odd, odd
C) even, odd
D) odd, even
E) even, equal
30) In the nuclear transmutation represented by
16
8
O(p, α)
13
7
N, the emitted particle is __________.
A) a beta particle.
B) an alpha particle.
C) a proton.
D) a positron.
E) a neutron.
31) Bombardment of uranium-235 with a neutron generates tellurium-135, 3 neutrons, and __________.
A) zirconium-98.
B) krypton-101.
C) krypton-103.
D) strontium-99.
E) zirconium-99.
32) The reaction shown below is responsible for creating 14C in the atmosphere. What is the
bombarding particle?
14
7
N + _____ →
14
6
C +
1
1
H
A) alpha particle
B) electron
C) neutron
D) positron
E) proton
33) How many neutrons are emitted when a californium-249 nucleus (Z=98) is bombarded with a
carbon-12 nucleus to produce a
257
104
Rf nucleus?
A) one
B) three
C) two
D) four
E) zero
25
34) How many neutrons are emitted when a californium-249 nucleus (Z=98) is bombarded with a
nitrogen-15 nucleus to produce a
260
105
Db nucleus?
A) two
B) three
C) four
D) one
E) zero
35) What order process is radioactive decay?
A) zeroth
B) first
C) second
D) third
E) fourth
36) Due to the nature of the positron, __________ is actually detected in positron emission tomography.
A) alpha radiation
B) beta radiation
C) gamma radiation
D) x-ray emission
E) neutron emission
37) 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
60
27
Co nucleus? (The mass of a cobalt-60 nucleus is 59.9338 amu.)
A) 27.7830
B) 0.5489
C) 0.5405
D) 0.0662
E) 0.4827
38) What is the typical percent of uranium-235 in the enriched UO2 pellets used in nuclear reactors?
A) 0.7
B) 1
C) 3
D) 10
E) 14
39) 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
40) What drives the turbine in a nuclear power plant?
A) the moderator
B) steam
C) the control rods
D) the primary coolant
E) UF6 gas
41) Who is credited with first achieving fission of uranium-235?
A) Fermi
B) Rutherford
C) Curie
D) Dalton
E) Faraday
42) When ionizing radiation enters the body, what is the predominant free radical produced?
A) H
B) H3O
C) protein
D) OH
E) H2O
43) The nuclear disintegration series of __________ is the source of radon-222 in soil.
A) 235U
B) 238U
C) 236Pb
D) 235Th
E) 14C
21.3 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) 3.23 × 10-15
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 0.275 mg of lead-206 for each milligram of uranium-238. The half-life for the decay
of uranium-238 to lead-206 is 4.5 × 109 yr. The rock was formed __________ yr ago.
A) 1.42 × 109
B) 9.62 × 108
C) 1.24 × 109
D) 1.79 × 109
E) 1.39 × 109
5) 131I has a half-life of 8.04 days. Assuming you start with a 3.53 mg sample of 131I, how many mg
will remain after 13.0 days?
A) 0.326
B) 0.268
C) 0.422
D) 2.30
E) 1.15
6) The decay of a radionuclide with a half-life of 2.3 × 105 years has a rate constant (in yr-1) equal to
__________.
A) 3.3 × 105
B) 3.0 × 10-6
C) 6.0 × 10-6
D) 2.8 × 103
E) 5.9 × 10-8
7) Potassium-40 decays to argon-40 with a half-life of 1.27 × 109 yr. The age of a mineral sample that
has a mass ratio of 40Ar to 40K of 0.712 is __________ yr.
A) 1.78 × 109
B) 1.11 × 109
C) 1.61 × 109
D) 6.83 × 108
E) 9.85 × 108
8) 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
9) 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
10) 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
11) Carbon-11 decays by positron emission:
11
6
C →
11
5
B +
0
1
e
The decay occurs with a release of 2.87 × 1011 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) 1.16 × 10-3
B) 3.48 × 105
C) 1.16 × 10-6
D) 8.62 × 102
E) 1.28 × 10-2
12) How much energy (in J) is produced when 0.082 g of matter is converted to energy?
A) 7.4 × 1018
B) 7.4 × 1012
C) 2.5 × 104
D) 7.4 × 1015
E) 2.5 × 107
21.4 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)
0
-1
e 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 initial element used to make cobalt-60 for cancer radiation therapy is __________.
11) The half-life for the beta decay of potassium-40 is 1.3 × 109 years. What is the rate constant for this
decay?
12) __________ discovered radioactivity.
13) Carbon-11, fluorine-18, oxygen-15 and nitrogen-13 are all used in the clinical diagnostic technique
known as __________.
14) What is the source of the tremendous energies produced by nuclear reactions?
15) Control rods in a nuclear reactor are composed of boron and __________.
16) The amount of fissionable material necessary to maintain a chain reactions is called the __________.
17) What was the purpose of the Manhattan project?
18) When living tissue is irradiated most of the energy is absorbed by __________.
19) The relative biological effectiveness (RBE) values of beta rays, gamma rays, and alpha rays are,
respectively
20) The major type of cancer caused by radiation is __________.
21) Radioactive seeds that are implanted into a tumor are coated with __________ to stop alpha and beta
ray penetration.
21.5 True/False Questions
1) Gamma radiation only changes the atomic number but not the mass number of a nucleus.
2) Positron emission causes a decrease of one in the atomic number.
3) The neutron/proton ratio of stable nuclei increases with increasing atomic number.
4) Charged particles are accelerated because the faster they move there is a greater chance of producing
a nuclear reaction.
5) Radioactive decay is a first order kinetic process.
6) In radioactive dating the ratio of carbon-12 to carbon-14 is related to the time of death of the animal
or plant under investigation.
7) In the formula k=0.693/t1/2, k is the decay constant.
8) The energy produced by the sun is the result of nuclear fusion.
9) The SI unit of an absorbed dose of radiation is the gray.
10) The relative biological effectiveness (RBE) is 10 fold greater for gamma radiation than for alpha
radiation.
21.6 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?
4) The use of radioisotopes in tracing metabolism is possible because __________.