Deck 11: Nuclear Chemistry

Question 1

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.

Answer 1

Atoms may not be changed into other atoms.

Question 2

Which of the following particles has a mass of 1 amu and a charge of 0?

A) neutron
B) proton
C) electron
D) positron

Answer 2

neutron

Question 3

When thorium-234 undergoes beta decay, what other product is formed?

A) thorium-233
B) protactinium-234
C) radium-88
D) uranium-238

Answer 3

protactinium-234

Question 4

When radium-223 undergoes alpha decay, what other product is formed?

A) radium-219
B) radium-224
C) actinium-224
D) radon-219

Question 5

Atoms that have the same atomic number but different numbers of neutrons are

A) radioactive.
B) isotopes.
C) impossible.
D) ions.

Question 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.

Question 7

An alpha particle is the same as a

A) helium-5 nucleus.
B) helium-4 nucleus.
C) hydrogen-1 nucleus.
D) neutron.

Question 8

Rn decays by emission of an alpha particle. The product of this decay is

A) Ra
B) Po
C) Ra
D) Rn

Question 9

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.

Question 10

Uranium-238 decays by emission of an alpha particle. The product of this decay is

A) U
B) Pa
C) Th
D) Ra

Question 11

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.

Question 12

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.

Question 13

Thorium-234 undergoes beta decay: Th → e + Q What is Q?

A) Pa
B) Ac
C) Th
D) Th

Question 14

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

Question 15

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.

Question 16

The following nuclear reaction is an example of Ra → He + Rn

A) alpha decay.
B) beta decay.
C) gamma decay.
D) an impossible reaction.

Question 17

Bi decays by beta emission. The product is

A) Bi
B) Po
C) Pa
D) Au

Question 18

The nucleon number decreases by 4 during what type of radioactive decay?

A) beta decay
B) alpha decay
C) gamma radiation
D) positron emission

Question 19

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.

Question 20

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.

Question 21

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

Question 22

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.

Question 23

Phosphorus-30 decays by positron emission. The product is

A) silicon-30.
B) phosphorus-29.
C) sulfur-30.
D) sulfur-29.

Question 24

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

Question 25

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

Question 26

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

Question 27

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%

Question 28

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

Question 29

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.

Question 30

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

Question 31

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.

Question 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

Question 33

The isotope that is used for the dating of brandy is

A) uranium-238.
B) lead-210.
C) carbon-14.
D) hydrogen-3.

Question 34

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

Question 35

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.

Question 36

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.

Question 37

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.

Question 38

The amount of a radioactive isotope that remains after two half-lives have passed is

A) 98%.
B) 75%.
C) 50%.
D) 25%.

Question 39

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

Question 40

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

Question 41

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.

Question 42

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.

Question 43

Radioisotopes have been used to determine the age of all of the following EXCEPT

A) brandy.
B) cloth.
C) living plants.
D) wood.

Question 44

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.

Question 45

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.

Question 46

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.

Question 47

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.

Question 48

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.

Question 49

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.

Question 50

In positron emission tomography (PET), a positron collides with an electron and the two particles disappear in a burst of

A) an alpha particle and a gamma ray.
B) two beta particles.
C) a neutron and an alpha particle.
D) two gamma rays.

Question 51

The radioisotope used to detect anemia is

A) gadolinium-153.
B) iron-59.
C) plutonium-238.
D) iodine-131.

Question 52

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.

Question 53

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

Question 54

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.

Question 55

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

Question 56

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

Question 57

Technetium-99^m is a radioisotope used in a variety of diagnostic tests. Technetium-99^m 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.

Question 58

Which one of the following is most penetrating?

A) He nucleus
B) beta particle
C) gamma ray
D) visible light

Question 59

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

Question 60

The medical application of cobalt-60 is

A) brain scans.
B) bone density determination
C) eye tumor detection.
D) radiation cancer therapy.

Question 61

The most stable elements have

A) a high binding energy per nucleon.
B) a low binding energy per nucleon.
C) a high proton to neutron ratio.
D) an atomic number above 92.

Question 62

Naturally occurring uranium contains approximately what percentage of uranium-235, the isotope that undergoes fission?

A) 0.72%
B) 10%
C) 50%
D) 100%

Question 63

The U.S. president who ordered the dropping of atomic bombs on the Japanese cities of Hiroshima and Nagasaki was

A) Bill Clinton.
B) Harry Truman.
C) Dwight Eisenhower.
D) George Bush.

Question 64

Critical mass is

A) the minimum amount of fissionable material that will sustain a chain reaction.
B) the maximum amount of fissionable material that will sustain a chain reaction.
C) the amount of fissionable material that produces the most energy when split.
D) the largest amount of fissionable material that can be obtained from isotopic enrichment.

Question 65

Gamma rays can be stopped by

A) a sheet of paper.
B) a thin aluminum sheet.
C) a block of wood.
D) several centimeters of lead.

Question 66

The often tedious process by which a naturally occurring mixture of isotopes is separated and concentrated is called

A) isotopic transmutation.
B) isotopic ionization.
C) isotopic synthesis.
D) isotopic enrichment.

Question 67

The source of the energy produced by the sun is

A) the burning of fossil fuels.
B) the fission of uranium-235.
C) the fusion of primarily hydrogen.
D) unknown.

Question 68

Radioactive alpha emitters pose the greatest potential health risk when they are

A) unshielded.
B) on the skin.
C) ingested.
D) all of the above

Question 69

In the famous relationship: E = mc², the symbol m represents

A) mass.
B) molecules.
C) momentum.
D) metastable.

Question 70

Which of the following was NOT a goal of the Manhattan project?

A) to isolate enriched uranium-235
B) to produce plutonium-239
C) constructing a bomb based on nuclear fission
D) to determine the amount of uranium-235 needed for an atomic power plant

Question 71

In nuclear fusion,

A) large unstable nuclei are fused together, and then split with the release of binding energy.
B) large, relatively unstable, nuclei are split releasing binding energy.
C) small, relatively stable, nuclei are split releasing binding energy.
D) smaller, relatively stable, nuclei are forced together to create a larger nucleus with the release of binding energy.

Question 72

UF₆ containing uranium-235 can be separated from UF₆ containing uranium-238 because

A) compounds containing uranium-235 react differently than compounds containing uranium-238.
B) UF₆ containing uranium-235 is lighter and will travel faster than UF₆ containing uranium-238.
C) UF₆ containing uranium-235 is lighter and will travel more slowly than UF₆ containing uranium-238.
D) They cannot be separated.

Question 73

Alpha particles can be stopped by a

A) sheet of paper.
B) block of wood.
C) thin sheet of aluminum.
D) all of these

Question 74

Although Albert Einstein is considered one of the greatest scientists of all time, his work generally did not involve much of an aspect that is traditionally associated with science. That aspect is

A) creativity.
B) mathematics.
C) theories.
D) experiments.

Question 75

Which process will result in an increase in the binding energy per nucleon?

A) fission of large radioactive nuclei
B) fusion of small nuclei
C) both A and B
D) neither A nor B

Question 76

Which type of radioactive emission is very similar to X-rays?

A) positron
B) electron
C) alpha
D) gamma ray

Question 77

Stagg Field, at the University of Chicago, is where

A) nuclear fission was discovered.
B) radioactivity was discovered.
C) nuclear fusion was discovered.
D) the first nuclear pile was built.

Question 78

Nuclear fission is a process by which the nucleus of an atom

A) splits into two or more fragments spontaneously.
B) is induced to split into two or more fragments by some external source.
C) combines with another nucleus to produce a larger nucleus.
D) loses a proton with the release of a large amount of energy.

Question 79

In the fission of uranium-235, which particle causes and propagates the chain reaction?

A) alpha particle
B) beta particle
C) neutron
D) electron

Question 80

The mass of a helium nucleus is slightly less than the sum of its parts (2 protons and 2 neutrons) because

A) some of the mass is converted to binding energy.
B) some of the mass is given to electrons.
C) the mass of protons and neutrons are not precisely known.
D) the mass of a proton is larger than the mass of a neutron.