Nuclear Chem

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AP Exam Review: Nuclear
1984
30. When 214
Po decays, the emission consists consecutively of an alpha particle, then two beta particles, and
84
finally another alpha particle. The resulting stable nucleus is
a) 206
Bi
d) 208
Pb
83
82
210
210
b) 83Bi
e) 81Tl
206
c) 82Pb
38. The radioactive decay of 146C to
a) beta particle emission
b) alpha particle emission
c) positron emission
14
N
7
occurs by the process of
d) electron capture
e) neutron capture
1989
18. For the types of radiation given, which of the following is the correct order of increasing ability to penetrate
a piece of lead?
a) Alpha particles<gamma rays<beta particles
d) Beta particles<gamma rays<alpha particles
b) Alpha particles<beta particles<gamma rays
e) Gamma rays<alpha particles<beta particles
c) Beta particles<alpha particles<gamma rays
38.
251
98
Xe +
Cf  2 n + 131
54
___
What is the missing product in the nuclear reaction represented above?
(A) 118
Mo
(D) 120
Ru
44
44
118
122
(B) 44Ru
(E) 46Pd
120
(C) 42Mo
1994
21. Correct statements about alpha particles include which of the following?
I. They have a mass number of 4 and a charge of +2.
II. They are more penetrating than beta particles.
III. They are helium nuclei.
(A) I only
(D) I and III
(B) III only
(E) II and I
(C) I and II
72. The nuclide 245Cm is radioactive and decays by the loss of one beta (-) particle. The product nuclide is
(A) 245Pu
(D) 250Cm
(B) 95Am
(E) 97Bk
248
(C) Cm
1999
48. If 87.5 percent of a sample of pure 131I decays in 24 days, what is the half-life of 131I?
a) 6 days
d) 14 days
b) 8 days
e) 21 days
c) 12 days
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2002
235
92
U + 01 n 
141
55
Cs + 3 01 n + X
23. Neutron bombardment of uranium can induce the reaction represented above. Nuclide X is which of the
following?
d. 92
Rb
37
a. 92
Br
35
94
e. 37Rb
b. 94 Br
c.
35
91
Rb
37
43. The atomic mass of copper is 63.55. Given that there are only two naturally occurring isotopes of copper,
63
Cu and 65Cu, the natural abundance of the 65Cu isotope must be approximately
a) 90%
d) 25 %
b) 70%
e) 10%
c) 50%
Free Response Questions
1997
8. Answer each of the following questions regarding radioactivity.
(a) Write the nuclear equation for decay of
239
94
Pu by alpha emission.
(b) Account for the fact that the total mass of the products of the reaction in part (a) is slightly less than that of
the original 239
.
94 Pu
(c) Describe how , , and  rays each behave when they pass through an electric field. Use the diagram
below to illustrate your answer.
(d) Why is it not possible to eliminate the hazard of nuclear waste by
the process of incineration?
2003 Form B
8. The decay of the radioisotope I-131 was studied in a laboratory. I-131 is known to decay by beta ( -10 e )
emission.
(a) Write a balanced nuclear equation for the decay of I-131.
(b) What is the source of the beta particle emitted from the nucleus?
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Multiple Choice Answers
1984
30. c)
38. a)
1989
18. b)
38. b)
1994
21. (D)
72. (E)
1999
48. b)
2002
23. d)
43. d)
Answer 1997 #8
(a)
239
94
Pu  24a +
235
92
U
(b) The mass defect has been converted into energy: ∆E = ∆m c2
(c) An alpha particle,  or He nuclei, has a 2+ charge and would be attracted to the (-) side of the electric field.
A beta particle, , or electron, has a single negative charge and is attracted to the positive side of the
electric field, but since it is much lighter and faster than an alpha it would not be as strongly deflected.
Gamma, , rays are not charged and, therefore, not deflected by the electric field.
(d) The half-life of a radionuclide is independent of its environment. Incineration will neither accelerate its
decay nor render it non-radioactive. Half-life is a function of its nucleus, incineration is a function of its
electrons.
Answer 2003 Form B
8. (a)
131
53
0
I ® 131
54 Xe + -1 e
(b) A neutron spontaneously decays to an electron and a proton.
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