Question 1

Why doesn't uranium ore spontaneously undergo a chain reaction?

Accepted Answer

A) Uranium ore must be "weapons' grade" in order for it to undergo chain reaction. 
B) Uranium ore is mostly non-fissionable isotope U-238 and undergoes a chain reaction only if mixed with a moderator to slow down the neutrons. 
C) Uranium ore does spontaneously undergo slow chain reaction over time finally resulting in it becoming lead. 
D) Uranium ore, mostly U-235, must be enriched with U-238 in order for it to undergo a chain reaction. 
A) Uranium ore must be "weapons' grade" in order for it to undergo chain reaction. 
B) Uranium ore is mostly non-fissionable isotope U-238 and undergoes a chain reaction only if mixed with a moderator to slow down the neutrons. 
C) Uranium ore does spontaneously undergo slow chain reaction over time finally resulting in it becoming lead. 
D) Uranium ore, mostly U-235, must be enriched with U-238 in order for it to undergo a chain reaction.

Question 2

Why might the following nuclear reaction not be very good for energy production in a fission reactor?   U →   Ba +   Kr + 1 neutron

Accepted Answer

A) The material only produces one neutron so the chain reaction will not be very efficient. 
B) The products are too large. 
C) There are too many products produced. 
D) The mass of the byproducts is too high and therefore the energy released will not be high enough. 
E) Interatomic attraction between the products will impede the efficient separation of the atoms from the unstable nuclei. 
A) The material only produces one neutron so the chain reaction will not be very efficient. 
B) The products are too large. 
C) There are too many products produced. 
D) The mass of the byproducts is too high and therefore the energy released will not be high enough. 
E) Interatomic attraction between the products will impede the efficient separation of the atoms from the unstable nuclei.

Question 3

If a nucleus of   Th absorbs a neutron and the resulting nucleus undergoes two successive beta decays (emitting electrons), what nucleus results?

Accepted Answer

A) Americium-232 
B) Plutonium-232 
C) Thorium-233 
D) Uranium-233 
A) Americium-232 
B) Plutonium-232 
C) Thorium-233 
D) Uranium-233

Question 4

What does Einstein's energy equation (E = mc2)say about the energy that is derived from nuclear fission reactions?

Accepted Answer

A) The energy released is due to the missing mass of the products compared to the mass of the starting materials. 
B) The energy is proportional to the mass of the atom undergoing fission. 
C) The energy is derived from the light that is emitted when the atom splits. 
D) The energy equation does not apply towards fission, only fusion. 
E) none of the above 
A) The energy released is due to the missing mass of the products compared to the mass of the starting materials. 
B) The energy is proportional to the mass of the atom undergoing fission. 
C) The energy is derived from the light that is emitted when the atom splits. 
D) The energy equation does not apply towards fission, only fusion. 
E) none of the above

Question 5

Which of the following nuclear equations correctly describes beta emission?

Accepted Answer

A)    Th →   Pa +   e 
B)    Th →   Ac +   e 
C)    Th →   Pa +   e 
D)    Th →   e 
E) none of the above 
A)    Th →   Pa +   e 
B)    Th →   Ac +   e 
C)    Th →   Pa +   e 
D)    Th →   e 
E) none of the above

Question 6

Which of the following statements about fusion is true?

Accepted Answer

A) Fusion reactions have no critical-mass requirement. 
B) Fusion is easier than fission. 
C) Fusion reactions can be easily controlled to make energy. 
D) Fusion produces no harmful radiation. 
E) none of the above 
A) Fusion reactions have no critical-mass requirement. 
B) Fusion is easier than fission. 
C) Fusion reactions can be easily controlled to make energy. 
D) Fusion produces no harmful radiation. 
E) none of the above

Question 7

What property of half-lives makes radioactive material so problematic?

Accepted Answer

A) There is no known way to shorten a half-life. 
B) Radioactivity is limited by the natural decay-time to stable isotopes. 
C) All half-lives are long. 
D) There is no known way to measure half-lives with any accuracy. 
E) both A and B 
A) There is no known way to shorten a half-life. 
B) Radioactivity is limited by the natural decay-time to stable isotopes. 
C) All half-lives are long. 
D) There is no known way to measure half-lives with any accuracy. 
E) both A and B

Question 8

Which of the following sources of radiation provides most of our yearly exposure?

Accepted Answer

A) background radiation 
B) smoke detectors 
C) living near nuclear power plants 
D) televisions (cathode ray tubes) 
E) dental and medical X-rays 
A) background radiation 
B) smoke detectors 
C) living near nuclear power plants 
D) televisions (cathode ray tubes) 
E) dental and medical X-rays

Question 9

How can a half-life be used to tell the age of a sample?

Accepted Answer

A) The half-life of an isotope is constant. 
B) The amount of radioactive form depends on the amount of radiation in the surroundings. 
C) The ratio between the radioactive form and the stable form depends on the archaeological record. 
D) The ratio between the radioactive form and stable form varies regularly with time. 
E) both C and D 
A) The half-life of an isotope is constant. 
B) The amount of radioactive form depends on the amount of radiation in the surroundings. 
C) The ratio between the radioactive form and the stable form depends on the archaeological record. 
D) The ratio between the radioactive form and stable form varies regularly with time. 
E) both C and D

Question 10

The age of the Dead Sea Scrolls was found by carbon-14 dating. Could this technique have worked if they were carved in stone tablets? Explain.

Accepted Answer

A) Yes, because there are appreciable levels of carbon even in stone. 
B) No, this method of dating requires a material that was once living. 
C) Yes, because X-ray images could be collected instead. 
D) No, the stones in the arid environment of the Dead Sea would have lost all of their carbon-14 by now. 
A) Yes, because there are appreciable levels of carbon even in stone. 
B) No, this method of dating requires a material that was once living. 
C) Yes, because X-ray images could be collected instead. 
D) No, the stones in the arid environment of the Dead Sea would have lost all of their carbon-14 by now.

Question 11

What are some of the optimistic worldwide changes that may follow the advent of successful fusion reactors?

Accepted Answer

A) Economies will be geared to relative abundance rather than scarcity. 
B) Humans will have more opportunities to focus on social issues, such as world hunger. 
C) There will be fewer hostilities between nations. 
D) all of the above 
A) Economies will be geared to relative abundance rather than scarcity. 
B) Humans will have more opportunities to focus on social issues, such as world hunger. 
C) There will be fewer hostilities between nations. 
D) all of the above

Question 12

Which of the following statements best describes the strong nuclear force?

Accepted Answer

A) The force is very strong but has a very short range. 
B) The electrical force is stronger than the nuclear force. 
C) The force is very strong and works over very long distances. 
D) The strength of the force increases with distance. 
E) The force has two sides: the light side and the dark side. 
A) The force is very strong but has a very short range. 
B) The electrical force is stronger than the nuclear force. 
C) The force is very strong and works over very long distances. 
D) The strength of the force increases with distance. 
E) The force has two sides: the light side and the dark side.

Question 13

If three samples have the half-lives listed below, which sample would remain radioactive the longest?

Accepted Answer

A) a sample with a half-life of 20 minutes 
B) a sample with a half-life of 20 hours 
C) a sample with a half-life of 20 years 
D) a sample with a half-life of 20 million years 
E) none of the above 
A) a sample with a half-life of 20 minutes 
B) a sample with a half-life of 20 hours 
C) a sample with a half-life of 20 years 
D) a sample with a half-life of 20 million years 
E) none of the above

Question 14

Which of the following provides the minimum amount of protection you need to block the following form of radiation? beta

Accepted Answer

A) lead suit 
B) suntan lotion 
C) thick leather 
D) T-shirt 
E) none of the above 
A) lead suit 
B) suntan lotion 
C) thick leather 
D) T-shirt 
E) none of the above

Question 15

Why is carbon better than lead as a moderator in nuclear reactors?

Accepted Answer

A) Carbon produces the high energy, high speed neutrons necessary for maintaining the nuclear chain reaction. 
B) Carbon slows down the neutrons making them more effective in stimulating the nuclear chain reaction. 
C) Lead absorbs the neutrons rather than allowing them to rebound to maintain the nuclear chain reaction. 
D) Lead slows down the neutrons making them less effective in stimulating the nuclear chain reaction. 
A) Carbon produces the high energy, high speed neutrons necessary for maintaining the nuclear chain reaction. 
B) Carbon slows down the neutrons making them more effective in stimulating the nuclear chain reaction. 
C) Lead absorbs the neutrons rather than allowing them to rebound to maintain the nuclear chain reaction. 
D) Lead slows down the neutrons making them less effective in stimulating the nuclear chain reaction.

Question 16

Which of the following provides the minimum amount of protection you need to block the following form of radiation? alpha

Accepted Answer

A) lead suit 
B) suntan lotion 
C) thick leather 
D) T-shirt 
E) none of the above 
A) lead suit 
B) suntan lotion 
C) thick leather 
D) T-shirt 
E) none of the above

Question 17

When the isotope bismuth-213 emits an alpha particle, what new element results?

Accepted Answer

A) lead 
B) platinum 
C) polonium 
D) thallium 
A) lead 
B) platinum 
C) polonium 
D) thallium

Question 18

The isotope Cesium-137, which has a half-life of 30 years, is a product of nuclear power plants. How long will it take for this isotope to decay to about one-sixteenth its original amount?

Accepted Answer

A) 480 years 
B) 240 years 
C) 120 years 
D) 960 years 
A) 480 years 
B) 240 years 
C) 120 years 
D) 960 years

Question 19

Does the average distance that a neutron travels through fissionable material before escaping increase or decrease when two pieces of fissionable material are assembled into one piece? Does this assembly increase or decrease the probability of an explosion?

Accepted Answer

A) The average distance increases while the probability of an explosion also increases. 
B) The average distance decreases while the probability of an explosion decreases. 
C) The average distance increases while the probability of an explosion decreases. 
D) The average distance decreases while the probability of an explosion increases. 
A) The average distance increases while the probability of an explosion also increases. 
B) The average distance decreases while the probability of an explosion decreases. 
C) The average distance increases while the probability of an explosion decreases. 
D) The average distance decreases while the probability of an explosion increases.

Question 20

Which of the following nuclear equations correctly describes alpha emission?

Accepted Answer

A)    Th →   Pa +   e 
B)    Th →   Ac +   e 
C)    Th →   Pa +   e 
D)    Th →   e 
E) none of the above 
A)    Th →   Pa +   e 
B)    Th →   Ac +   e 
C)    Th →   Pa +   e 
D)    Th →   e 
E) none of the above

Exam 13: The Atomic Nucleus and Radioactivity

Why doesn't uranium ore spontaneously undergo a chain reaction?

Why might the following nuclear reaction not be very good for energy production in a fission reactor? U → Ba + Kr + 1 neutron

If a nucleus of Th absorbs a neutron and the resulting nucleus undergoes two successive beta decays (emitting electrons), what nucleus results?

What does Einstein's energy equation (E = mc2)say about the energy that is derived from nuclear fission reactions?

Which of the following nuclear equations correctly describes beta emission?

Which of the following statements about fusion is true?

What property of half-lives makes radioactive material so problematic?

Which of the following sources of radiation provides most of our yearly exposure?

How can a half-life be used to tell the age of a sample?

The age of the Dead Sea Scrolls was found by carbon-14 dating. Could this technique have worked if they were carved in stone tablets? Explain.

What are some of the optimistic worldwide changes that may follow the advent of successful fusion reactors?

Which of the following statements best describes the strong nuclear force?

If three samples have the half-lives listed below, which sample would remain radioactive the longest?

Which of the following provides the minimum amount of protection you need to block the following form of radiation? beta

Why is carbon better than lead as a moderator in nuclear reactors?

Which of the following provides the minimum amount of protection you need to block the following form of radiation? alpha

When the isotope bismuth-213 emits an alpha particle, what new element results?

The isotope Cesium-137, which has a half-life of 30 years, is a product of nuclear power plants. How long will it take for this isotope to decay to about one-sixteenth its original amount?

Does the average distance that a neutron travels through fissionable material before escaping increase or decrease when two pieces of fissionable material are assembled into one piece? Does this assembly increase or decrease the probability of an explosion?

Which of the following nuclear equations correctly describes alpha emission?

Patterns of Motion and Equilibrium

Newtons Laws of Motion

Momentum and Energy

Gravity, Projectiles, and Satellites

Fluid Mechanics

Thermal Energy and Thermodynamics

Heat Transfer and Change of Phase

Static and Current Electricity

Magnetism and Electromagnetic Induction

Waves and Sound

Light

Atoms and the Periodic Table

Elements of Chemistry

How Atoms Bond and Molecules Attract

Mixtures

How Chemicals React

Two Classes of Chemical Reactions

Organic Compounds

Rocks and Minerals

Plate Tectonics and Earths Interior

Shaping Earths Surface

Geologic Timereading the Rock Record

The Oceans, Atmosphere, and Climatic Effects

Driving Forces of Weather

The Solar System

Stars and Galaxies

The Structure of Space and Time

Prologue: the Nature of Science

Filters

What does Einstein's energy equation (E = mc²)say about the energy that is derived from nuclear fission reactions?