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Chemistry for Changing Times, 14e (Hill/McCreary)
Chapter 11 Nuclear Chemistry
11.1 Multiple Choice Questions
1) If it were possible to obtain a cubic centimeter of pure atomic nuclei, its mass would be approximately
A) 1 g.
B) 19 g.
C) 1.0 × 108 metric tons.
D) 1 kg.
2) The diameter of an atom is 100,000 times as great as the diameter of its nucleus. If an atom could be
expanded to the size of a classroom the nucleus would be about the size of a
A) BB.
B) marble.
C) basketball.
D) period at the end of a sentence.
3) The major part of the average exposure of humans to radiation comes from
A) nuclear power plants.
B) diagnostic X-rays.
C) other human made sources.
D) naturally occurring sources.
4) Cosmic rays are
A) high energy radiation produced by the sun.
B) high energy radiation produced in the ozone layer.
C) high energy radiation produced by the earth’s core.
D) none of these
5) What does not describe ionizing radiation?
A) Ionizing radiation can devastate living cells by interfering with their normal chemical processes.
B) Ionizing radiation can cause changes in the molecules of DNA in reproductive cells.
C) Ionizing radiation can cause molecules to be split into free radicals, which can disrupt vital cellular
processes.
D) Ionizing radiation can affect blood sugar levels and causes diabetes.
6) Radiation with enough energy to knock electrons off atoms or molecules is known as
A) electron capture.
B) fundamental radiation
C) ionizing radiation.
D) transmuting radiation.
7) All of the following are known to be forms of ionizing radiation EXCEPT
A) radio waves.
B) gamma rays.
C) ultraviolet radiation.
D) X-rays.
8) Atoms that have the same atomic number but different numbers of neutrons are
A) radioactive.
B) isotopes.
C) impossible.
D) ions.
9) The following nuclear reaction is an example of
Ra → He + Rn
A) alpha decay.
B) beta decay.
C) gamma decay.
D) an impossible reaction.
10) An alpha particle is the same as a
A) helium-5 nucleus.
B) helium-4 nucleus.
C) hydrogen-1 nucleus.
D) neutron.
11) Thorium-234 undergoes beta decay:
Th → e + Q
What is Q?
A) Pa
B) Ac
C) Th
D) Th
12) Uranium-238 decays by emission of an alpha particle. The product of this decay is
A) U
B) Pa
C) Th
D) Ra
13) When thorium-234 undergoes beta decay, what other product is formed?
A) thorium-233
B) protactinium-234
C) radium-88
D) uranium-238
14) When radium-223 undergoes alpha decay, what other product is formed?
A) radium-219
B) radium-224
C) actinium-224
D) radon-219
15) Rn decays by emission of an alpha particle. The product of this decay is
A) Ra
B) Po
C) Ra
D) Rn
16) Bi decays by beta emission. The product is
A) Bi
B) Po
C) Pa
D) Au
17) The process of beta emission can be envisioned as the
A) conversion of a proton to a neutron and electron. The electron is emitted.
B) conversion of a neutron to a proton and electron. The electron is emitted.
C) conversion of a neutron to a proton and electron. The proton is emitted.
D) conversion of a proton to a neutron and electron. The proton is emitted.
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18) Which of the following particles has a mass of 1 amu and a charge of 0?
A) neutron
B) proton
C) electron
D) positron
19) The nucleon number decreases by 4 during what type of radioactive decay?
A) beta decay
B) alpha decay
C) gamma radiation
D) positron emission
20) With the discovery of nuclear reactions, and particularly transmutation, which postulates of Dalton’s
atomic theory must be modified?
A) Matter is composed of atoms.
B) Atoms of the same element are the same; atoms of different elements are different.
C) Atoms combine with other atoms in fixed, whole number ratios.
D) Atoms may not be changed into other atoms.
21) Phosphorus-30 decays by positron emission. The product is
A) silicon-30.
B) phosphorus-29.
C) sulfur-30.
D) sulfur-29.
22) The process of positron emission can be considered as the
A) conversion of a neutron to a proton and a positron. The positron is emitted.
B) conversion of a neutron to a proton and an electron. The electron is emitted.
C) conversion of a proton to a neutron and a positron. The neutron is emitted.
D) conversion of a proton to an neutron and a positron. The positron is emitted.
23) The process of electron capture can be considered as the
A) conversion of an electron and a proton to a neutron.
B) conversion of an electron and a neutron to a proton.
C) conversion of a proton to a neutron and an electron. The electron is emitted.
D) conversion of a neutron to a proton and an electron. The electron is emitted.
24) The process of alpha decay results in what change in the atomic number?
A) a decrease of 2
B) a decrease of 1
C) an increase of 1
D) no change
25) The process of beta decay results in what change in the atomic number?
A) a decrease of 2
B) a decrease of 1
C) an increase of 1
D) no change
26) The process of positron emission results in what change in the atomic number?
A) a decrease of 2
B) a decrease of 1
C) an increase of 1
D) no change
27) The process of electron capture results in what change in the atomic number?
A) a decrease of 2
B) a decrease of 1
C) an increase of 1
D) no change
28) One difference between a chemical reaction and a nuclear reaction is that in a nuclear reaction
A) atoms retain their identity.
B) atoms often change from one element to another.
C) only the valence electrons are involved.
D) only small amounts of energy are absorbed or emitted.
29) After five half-lives, what percentage of the original radioactive isotope remains in a sample?
A) 0%
B) 50%
C) 3.13%
D) 6.25%
30) Nitrogen-13 has a half-life of 10 minutes. How much of a 128 mg sample would remain after 40
minutes?
A) 4 mg
B) 8 mg
C) 16 mg
D) 32 mg
31) Nitrogen-13 has a half-life of 10 minutes. How much of a 128 mg sample would remain after 20
minutes?
A) 0 mg
B) 4 mg
C) 16 mg
D) 32 mg
32) Sodium-24 has a half-life of 15 hours. How much of a 20 mg sample would remain after two half–
lives?
A) 0 mg
B) 2 mg
C) 5 mg
D) 10 mg
33) The amount of a radioactive isotope that remains after two half-lives have passed is
A) 98%.
B) 75%.
C) 50%.
D) 25%.
34) Exposure to radioactive material is considered safe after 10 half–lives because
A) less than a tenth of 1% of the material remains.
B) less than 12.5% of the material remains.
C) ten is an even number.
D) all of the material will have decayed at that time.
35) Plants incorporate carbon as long they live. Once a plant dies, it takes how many years for 75% of the
carbon-14 to decay (half-life of C-14 is 5730 years)?
A) 573 yrs
B) 2865 yrs
C) 5730 yrs
D) 11460 yrs
36) Carbon-14 dating of ancient objects is particularly effective because C–14
A) has the shortest half-life.
B) is continuously produced in the upper atmosphere and its ratio to C-12 in living systems and the
environment is constant.
C) is a stable isotope and is therefore particularly easy to work with.
D) decays by a simple fission reaction.
37) In carbon-14 dating,
A) the radioactivity of carbon is artificially induced.
B) the radioactivity of carbon occurs naturally.
C) radioactive carbon is added to the sample to be dated.
D) none of the above
38) The isotope that is used for the dating of brandy is
A) uranium-238.
B) lead-210.
C) carbon-14.
D) hydrogen-3.
39) A piece of fossilized wood has a carbon-14 radioactivity that is 1/4 that of new wood. The half-life of
carbon-14 is 5730 years. How old is the cloth?
A) 1 × 5730 = 5730 years
B) 2 × 5730 = 11,460 years
C) 3 × 5730 = 17,190 years
D) 0.25 × 5730 = 1432 years
40) A piece of cloth is dated using carbon-14. The cloth is determined to be 1400 years old. The half-life
of C-14 is 5730 years. The C-14 radioactivity in the cloth will be ________ the radioactivity in a new cloth.
A) greater than
B) the same as
C) less than
D) Radioactivity cannot be predicted from the above information.
41) Radioisotopes have been used to determine the age of all of the following EXCEPT
A) brandy.
B) cloth.
C) living plants.
D) wood.
42) The bombardment of nitrogen-14 with alpha particles produces oxygen-17 and a proton. This process
is called
A) alpha emission.
B) transmutation.
C) isotopic enrichment.
D) fission.
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43) In 1932, James Chadwick bombarded beryllium-9 with alpha particles. One product was a neutron.
This led to the direct experimental verification of the existence of neutrons. The other product of
Chadwick’s nuclear reaction was
A) nitrogen-14.
B) carbon-12.
C) boron-12.
D) helium-4.
44) When nitrogen-14 is bombarded by alpha particles , a proton is produced. What other particle is
emitted?
A) a neutron
B) oxygen-16
C) a positron
D) oxygen-17
45) Ernest Rutherford bombarded nitrogen-14 with alpha particles and produced oxygen-17 and a
proton. What was the significance of this experiment?
A) It showed that most of the mass of an atom is in its nucleus.
B) It was the first time that protons were produced.
C) It showed that protons were part of the nucleus for an atom other than hydrogen.
D) It showed that the nucleus contains protons and neutrons.
46) Which of the following resulted in the first demonstration of artificial transmutation?
A) Rutherford’s bombardment of nitrogen-14 with alpha particles
B) Fermi and Segre’s bombardment of uranium atoms with neutrons
C) the change of lead into gold by alchemists in the 14th century
D) Goldstein’s production of protons in a gas discharge tube
47) Which of the following statements about transmutation is true? In transmutation,
A) an atom of gold will be produced.
B) the original element changes into a different element.
C) the particles in the nucleus of the product are the same as the particles in the nucleus of the starting
atom.
D) you need to balance electrons.
48) Transmutation
A) can be carried out by chemical means, but not nuclear processes.
B) can be carried out by chemical means and nuclear processes.
C) cannot be carried out by chemical means but can be accomplished by nuclear processes.
D) cannot be carried out by chemical means or nuclear processes.
49) The use of radioisotopes as tracers in medical and environmental research takes advantage of the fact
that isotopes
A) generally behave identically in chemical and physical processes.
B) generally behave differently in chemical and physical processes.
C) have different masses.
D) none of the above
50) Which of the following statements about the use of radioisotopes to irradiate foods is NOT true?
A) Radioisotopes kill microorganisms that cause food spoilage.
B) The taste and appearance of irradiated food undergoes a major change.
C) There is no residual radiation left in the food after irradiation.
D) Irradiation has been used for years in some countries.
51) Radioisotopes have been used as tracers in a variety of applications because
A) radioactive isotopes of an element have the same chemical properties as nonradioactive isotopes.
B) it is easy to follow the movement of a radioactive isotope.
C) the decay products are easily detected.
D) All of the above are true.
52) Which one of the following radioactive isotopes is useful in the investigation of thyroid problems?
A) Uranium-235
B) Barium-120
C) Iodine–131
D) Cesium-145
53) Positron emission tomography (PET) is a
A) therapy for cancer using positrons.
B) diagnostic technique for monitoring dynamic processes in the body, such as brain activity.
C) device for containing a nuclear fusion reaction.
D) mechanism for transmutation of elements.
54) Technetium-99m is a radioisotope used in a variety of diagnostic tests. Technetium–99m has a short
half-life (6 hr). The advantage of a short half-life for diagnostic purposes is
A) the radioactivity is easier to monitor.
B) the radioactivity does not linger in the body.
C) the radioactivity lasts for a long time.
D) the chemical reactions induced by the technetium are more rapid.
55) The medical application of cobalt-60 is
A) brain scans.
B) bone density determination
C) eye tumor detection.
D) radiation cancer therapy.
56) Gadolinium-153 is the most widely used radioisotope in medicine. It is used for the detection of
A) lung tumor.
B) skin cancer.
C) osteoporosis.
D) heart problems.
57) The radioisotope used to detect anemia is
A) gadolinium-153.
B) iron-59.
C) plutonium-238.
D) iodine-131.
58) The radioactive decay of 99mTc to 99Tc MUST occur with the emission of
A) an alpha particle alone.
B) two beta particles.
C) a gamma ray alone.
D) the combination of a beta particle and a gamma ray.