Chem 1412- Home-Work 8
1.
2.
3.
How many neutrons and protons (nucleons) does an atom with the symbol
have?
A. 33
B. 16
C. 49
D. 16
E. None of these.
A radioisotope decays to give an alpha particle and Pb-208. What was the original
element?
A. Se
B. Bi
C. Po
D. Hg
E. Rn
Predict the other product of the following nuclear transformation.
A.
B.
C.
D.
E.
4.
In the uranium-238 decay series there are eight radioisotopes starting with
that decay
by alpha emission, and six radioisotopes that decay by beta emission. The final product of
this series is a stable isotope. The symbol for this product is
A.
B.
C.
D.
E.
None of these.
5.
Sulfur-35 decays by beta emission. The decay product is
A.
B.
C.
D.
E.
6.
7.
8.
9.
When a nucleus undergoes radioactive decay, its new mass number is
a) always less than its original mass number.
b) always more than its original mass number.
c) always the same as its original mass number.
d) never less than its original mass number.
e) never more than its original mass number.
What fraction of radioactive atoms remains in a sample after six half-lives?
A. zero
B. 1/6
C. 1/16
D. 1/32
E. 1/64
Which isotope, when bombarded with nitrogen-15, yields the artificial isotope dubnium260 plus 4 neutrons?
A. californium-245
B. thorium-257
C. nobelium-245
D. californium-249
E. dubnium-249
In the following reaction, identify X.
A.
B.
C.
D.
E.
10. Polonium-208 is an alpha emitter with a half-life of 2.90 years. How many milligrams of
polonium from an original sample of 2.00 mg will remain after 8.00 years?
A.
B.
C.
D.
E.
0.147 mg
0.296 mg
0.725 mg
6.77 mg
1.90 mg
11.
Which of these is not a transuranium element?
a)
neptunium
b)
plutonium
c)
americium
d)
curium
e)
thorium
12.
When
13.
235
92
U is bombarded with one neutron, fission occurs, and the products are three neutrons,
a)
139
56
b)
90
37
c)
143
55
d)
89
37
Rb .
e)
88
37
Rb .
144
55
Ba .
Rb .
Cs .
Which of the following is the most probable mode of radioactive decay for the radioactive nuclide
a)
b)
c)
d)
e)
Cs , and
40
17
Cl ?
alpha emission
beta emission
positron emission
neutron emission
gamma emission
14.
A curie is
a)
the quantity of energy required to accelerate an electron by 1 V.
b)
a unit of radiation dosage.
c)
a measure of radioactive disintegrations per second.
d)
a very small unit of volume used for radioactive tracers in isotope dilution experiments.
e)
the safe limit for annual radiation exposure in the United States.
15.
Consider a certain type of nucleus that has a rate constant of 2.01 × 10 -2 min-1. Calculate the time required for
the sample to decay to one-fourth of its initial value.
a)
2.01 min
b)
0.0402 min
c)
34.5 min
d)
43.1 min
e)
69.0 min
16.
The half-life of the radioactive nuclide 84Se is 3.3 min. What is the activity of a 1.8-µg sample of 84Se? The
molar mass of 84Se is 83.918 g/mol. (1 Ci = 3.700 × 10 10 disintegrations/s)
a)
7.3 × 104 Ci
b)
1.1 × 10–10 Ci
c)
1.8 × 103 Ci
d)
1.6 × 10–16 Ci
e)
1.2 × 103 Ci
17.
The half-life of the radioisotope 158Eu is 0.77 h. How much time is required for a 160.0-g sample of 158Eu to
decay to 2.07 g?
a)
3.0 h
b)
4.0 h
c)
6.0 h
d)
2.1 h
e)
4.8 h
18.
Which of the following nuclides will produce 192Pt upon undergoing beta decay?
192
a)
Ir
196
b)
Hg
192
c)
Au
188
d)
Os
193
e)
Pt
19.
40
20.
The radioactive nuclide, 22Na, with a half-life of 23 s, undergoes decay by emitting a positron. What is the
nuclear composition of the product nuclide?
a)
12 protons and 10 neutrons
b)
11 protons and 11 neutrons
c)
11 protons and 10 neutrons
d)
10 protons and 12 neutrons
e)
9 protons and 12 neutrons
Ar can be prepared by electron capture from
36
a)
Cl.
40
b)
K.
41
c)
Ar.
40
d)
Ca.
33
e)
S