Chapter 21. Nuclear Chemistry
1. Indicate the missing word or words in the following definition: “Radioactive is the term used
to describe nuclides that possess ________ nuclei that spontaneously emit radiation.”
A.
B.
C.
D.
E.
unstable
abnormally large
nonspherical
abnormally small
elongated
2. Strontium-83 has a half life of 32 hours. What fraction of a 10 mg sample of 83Sr will be left
after 96 hours?
A.
B.
C.
D.
E.
50%
25%
12.5%
6.25%
3.13%
3. Which is an example of beta particle bombardment?
A.
0
14
14
6 C  1  7 N
B.
0
87
87
37 Rb  1e  36 Kr
2
3
4
1
1 H  1 H  2 He  0 n
235
1
135
97
1
92 U  0 n  53 I  39 Y  4 0 n
C.
D.
4. Californium-251 undergoes ________ to produce curium-247.
251
98 Cf
A.
B.
C.
D.
E.
 247
96 Cm 
gamma-ray emission
beta-particle decay
neutron decay
alpha-particle decay
positron decay
5. The bombardment of 147 N with 10 n nuclei gives two products, one of which is 11 H. The other
product is ________.
A.
14
6C
B.
13
6C
C.
14
8N
D.
14
6N
E.
14
8N
6. In nuclear power plants ________.
A.
B.
C.
D.
E.
the fission process is used to generate steam to turn a turbine to produce electricity
uranium atoms are changed directly into electrical energy
steam is produced by passing water directly over a radioactive material
the principles of operation are very different from those for a coal-fired plant
emitted -particles are captured directly as electricity
7. The decay of
A.
B.
C.
D.
E.
85
36 Kr
to
85
37 Rb
alpha particle
beta particle
neutron
proton
positron
8. How many neutrons does
A.
B.
C.
D.
E.
occurs through the emission of a(n) ________.
21
23
25
46
67
46
21
Sc have?

9. Identify the missing product in the following nuclear reaction:
238
92






A.
B.
C.
D.
E.
U   _______ + 42 He
242
94
234
90
242
90
234
92
232
92
Pu
Th
Th
U
U

10. Analysis of a 4.50-mg sample of a newly discovered isotope showed that only 3.25 mg of the
isotope remained after 29.6 h. What is the half-life of the isotope?
A.
B.
C.
D.
E.
47.6 h
53.4 h
58.0 h
63.0 h
71.2 h
11. When 235
92 U is bombarded with one neutron, fission occurs. The products are two neutrons,
144
55 Cs, and
 A.
B.

C.
D.

E.

139
56
90
37
143
55
89
37
94
36
Ba
Rb
Cs
Rb
Kr

 12. The half-life of the radioisotope
sample to decay to 1.25 g?

A.
B.
C.
D.
E.
3.5 h
4.5 h
6.0 h
7.0 h
8.5 h
130
55
Cs is 30 minutes. How long would it take for a 160.0-g

13. The nuclear reaction
14
C6 ------>
14
N7 + 0e-1
is an example of
(a)
(b)
(c)
(d)
(e)
nuclear fusion
nuclear fission
natural transmutation
artificial transmutation
none of the above
14. Identify the missing particle in the following equation:
238
U92 ------> 4He2 + ?
(a) 242Pu94
(b) 234Th90
(c) 242Th90
(d) 234U92
(e) none of these
15. Atoms with a given number of protons, but with a different number of neutrons are called
(a) Isomers
(b) Isotones
(c) Isotopes
(d) Isochrones
(e) Ionofores
16. Which equation is an example of artificial transmutation?
(a) 92U238 ------> 2He4 + 90Th234
(b) 13Al27 + 2He4 ------> 15P30 + 0n1
(c) 6C14 ------> 7N14 + -1e0
(d) 88Ra226 ------> 2He4 + 86Ra222
17. 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 change.
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
18. The missing product from this reaction is
121
A)
B)
C)
D)
E)
4
He2
e-1
1
n0
0
e1
none of the above
0
I53  121Te52 +