Question 1

Why is carbon better than lead as a neutron absorber 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 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 slows down the neutrons making them less effective in stimulating the nuclear chain reaction.

Question 2

Is the mass of an atomic nucleus greater or less than the sum of the masses of the nucleons composing it? Why don't the nucleon masses add up to the total nuclear mass?

Accepted Answer

A) Greater. We need to add the masses of the surrounding electrons to the masses of the nucleons. 
B) Neither. The mass of the atomic nucleus is exactly the sum of the masses of the nucleons. 
C) Less. The individual nucleons have greater mass when separated from the nucleus. This additional mass is a result of the energy of separation. 
D) Greater. The mass of the atomic nucleus also has mass of the "atomic glue" that holds the nucleons together in the nucleus. 
A) Greater. We need to add the masses of the surrounding electrons to the masses of the nucleons. 
B) Neither. The mass of the atomic nucleus is exactly the sum of the masses of the nucleons. 
C) Less. The individual nucleons have greater mass when separated from the nucleus. This additional mass is a result of the energy of separation. 
D) Greater. The mass of the atomic nucleus also has mass of the "atomic glue" that holds the nucleons together in the nucleus.

Question 3

A certain radioactive element has a half-life of one hour. If you start with a 1-g sample of the element at noon, how much of this same element will be left at 3:00 PM?

Accepted Answer

A) 0.5 gram 
B) 0.25 gram 
C) 0.125 gram 
D) 0.0625 gram 
A) 0.5 gram 
B) 0.25 gram 
C) 0.125 gram 
D) 0.0625 gram

Question 4

Which of the following statements regarding a nucleon is true in regards to nuclear reactions?

Accepted Answer

A) A nucleon inside a nucleus has a lower mass than a nucleon outside of the nucleus. 
B) The number of nucleons changes in a nuclear reaction, therefore the mass changes. 
C) A nucleon has a higher energy inside a nucleus, and releases it when it undergoes nuclear reactions. 
D) A nucleon's mass is constant. 
E) A nucleon is more stable outside the nucleus. 
A) A nucleon inside a nucleus has a lower mass than a nucleon outside of the nucleus. 
B) The number of nucleons changes in a nuclear reaction, therefore the mass changes. 
C) A nucleon has a higher energy inside a nucleus, and releases it when it undergoes nuclear reactions. 
D) A nucleon's mass is constant. 
E) A nucleon is more stable outside the nucleus.

Question 5

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 6

Nuclear fission is known to be commonly produced ________.

Accepted Answer

A) only by humans 
B) within the Earth's mantle 
C) within the Sun 
D) by humans, within the Earth's mantle, and also within the Sun 
A) only by humans 
B) within the Earth's mantle 
C) within the Sun 
D) by humans, within the Earth's mantle, and also within the Sun

Question 7

In the 19th century the famous physicist Lord Kelvin estimated the age of Earth to be much much less than its present estimate. What information did Kelvin not have to account for his error?

Accepted Answer

A) Lord Kelvin knew only classical physics and had no knowledge of anthropological dating. 
B) Lord Kelvin had no knowledge of radio waves for measuring distance and age of planets since they have not yet been introduced into science. 
C) Lord Kelvin was not aware of radioactive decay, a source of energy to keep Earth warm for billions of years. 
D) Lord Kelvin never gave any estimate of the age of Earth. 
A) Lord Kelvin knew only classical physics and had no knowledge of anthropological dating. 
B) Lord Kelvin had no knowledge of radio waves for measuring distance and age of planets since they have not yet been introduced into science. 
C) Lord Kelvin was not aware of radioactive decay, a source of energy to keep Earth warm for billions of years. 
D) Lord Kelvin never gave any estimate of the age of Earth.

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

Which of the following nuclear equations correctly describes alpha emission?

Accepted Answer

A)    U →   Th +   He 
B)    U →   U +   He 
C)    U →   Pu +   He 
D)    U →   He 
E) none of the above 
A)    U →   Th +   He 
B)    U →   U +   He 
C)    U →   Pu +   He 
D)    U →   He 
E) none of the above

Question 10

Why are smaller nuclei such as carbon-14 often radioactive? (carbon-12 is the most common and most stable form of carbon.)

Accepted Answer

A) The attractive force of the nucleons has a limited range. 
B) The isolated neutron is not stable and will undergo spontaneous transformation into a proton and an electron. 
C) Hmmm... mysterious are the ways of the force. 
D) both A and B 
E) none of the above 
A) The attractive force of the nucleons has a limited range. 
B) The isolated neutron is not stable and will undergo spontaneous transformation into a proton and an electron. 
C) Hmmm... mysterious are the ways of the force. 
D) both A and B 
E) none of the above

Question 11

Which of the following statements about fission is true?

Accepted Answer

A) The amount of energy released in the fission of large nuclei is very large. 
B) The amount of energy released in the fusion of small nuclei is very large. 
C) Bombarding a nucleus with neutrons always leads to fission. 
D) The fragments of a fusion reaction are always the same size. 
E) none of the above 
A) The amount of energy released in the fission of large nuclei is very large. 
B) The amount of energy released in the fusion of small nuclei is very large. 
C) Bombarding a nucleus with neutrons always leads to fission. 
D) The fragments of a fusion reaction are always the same size. 
E) none of the above

Question 12

Which type of radiation is being emitted in the following incomplete nuclear equation?   Po →   Pb + ??

Accepted Answer

A) alpha 
B) beta 
C) gamma 
D) A and B 
E) none of the above 
A) alpha 
B) beta 
C) gamma 
D) A and B 
E) none of the above

Question 13

Which of the following is a major advantage of nuclear-fission-based power plants?

Accepted Answer

A) The amount of energy per kilogram of fuel is greater than any other fuel source. 
B) The byproducts of the fission process are radioactive and have very long half-lives. 
C) The reactors can be used to produce their own fuel. 
D) The power plants are complex and there are many safety requirements to prevent contamination of the environment. 
E) A and C 
A) The amount of energy per kilogram of fuel is greater than any other fuel source. 
B) The byproducts of the fission process are radioactive and have very long half-lives. 
C) The reactors can be used to produce their own fuel. 
D) The power plants are complex and there are many safety requirements to prevent contamination of the environment. 
E) A and C

Question 14

If three samples have the half-lives listed below, which is the most radioactive?

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 15

What is a half-life?

Accepted Answer

A) It is the time it takes for 1/2 of the material to undergo radioactive decay. 
B) It is the time needed until 1/2 of the radiation is gone. 
C) It is the time it takes for 1/2 of the material to decompose. 
D) It is half of the lifetime of the radioactivity in a sample. 
E) all of the above 
A) It is the time it takes for 1/2 of the material to undergo radioactive decay. 
B) It is the time needed until 1/2 of the radiation is gone. 
C) It is the time it takes for 1/2 of the material to decompose. 
D) It is half of the lifetime of the radioactivity in a sample. 
E) all of the above

Question 16

Uranium-235 releases an average of 2.5 neutrons per fission, while plutonium-239 releases an average of 2.7 neutrons per fission. Which of these elements might you therefore expect to have the smaller critical mass?

Accepted Answer

A) plutonium-239 
B) uranium-235 
C) The number of neutrons per fission will not effect the size of critical mass. 
D) The critical mass of these elements cannot be determined from only the number of neutrons per fission. 
A) plutonium-239 
B) uranium-235 
C) The number of neutrons per fission will not effect the size of critical mass. 
D) The critical mass of these elements cannot be determined from only the number of neutrons per fission.

Question 17

During transmutation ________.

Accepted Answer

A) protons decay into neutrons 
B) neutrons decay into protons 
C) alpha particles are absorbed by nuclei 
D) all of the above 
A) protons decay into neutrons 
B) neutrons decay into protons 
C) alpha particles are absorbed by nuclei 
D) all of the above

Question 18

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 change in mass of the nucleus 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 change in mass of the nucleus 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 19

The strong nuclear force is very sensitive to ________.

Accepted Answer

A) electromagnetism 
B) distance 
C) the weak nuclear force 
D) mass 
A) electromagnetism 
B) distance 
C) the weak nuclear force 
D) mass

Question 20

Complete the following nuclear equation:   Tl →   Pb + ??

Accepted Answer

A)    e 
B)    He 
C) gamma ray 
D) both A and B 
E) none of the above 
A)    e 
B)    He 
C) gamma ray 
D) both A and B 
E) none of the above

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

Is the mass of an atomic nucleus greater or less than the sum of the masses of the nucleons composing it? Why don't the nucleon masses add up to the total nuclear mass?

A certain radioactive element has a half-life of one hour. If you start with a 1-g sample of the element at noon, how much of this same element will be left at 3:00 PM?

Which of the following statements regarding a nucleon is true in regards to nuclear reactions?

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

Nuclear fission is known to be commonly produced ________.

In the 19th century the famous physicist Lord Kelvin estimated the age of Earth to be much much less than its present estimate. What information did Kelvin not have to account for his error?

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

Which of the following nuclear equations correctly describes alpha emission?

Why are smaller nuclei such as carbon-14 often radioactive? (carbon-12 is the most common and most stable form of carbon.)

Which of the following statements about fission is true?

Which type of radiation is being emitted in the following incomplete nuclear equation? Po → Pb + ??

Which of the following is a major advantage of nuclear-fission-based power plants?

If three samples have the half-lives listed below, which is the most radioactive?

What is a half-life?

Uranium-235 releases an average of 2.5 neutrons per fission, while plutonium-239 releases an average of 2.7 neutrons per fission. Which of these elements might you therefore expect to have the smaller critical mass?

During transmutation ________.

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

The strong nuclear force is very sensitive to ________.

Complete the following nuclear equation: Tl → Pb + ??

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Exam 5: The Atomic Nucleus

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

Is the mass of an atomic nucleus greater or less than the sum of the masses of the nucleons composing it? Why don't the nucleon masses add up to the total nuclear mass?

A certain radioactive element has a half-life of one hour. If you start with a 1-g sample of the element at noon, how much of this same element will be left at 3:00 PM?

Which of the following statements regarding a nucleon is true in regards to nuclear reactions?

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

Nuclear fission is known to be commonly produced ________.

In the 19th century the famous physicist Lord Kelvin estimated the age of Earth to be much much less than its present estimate. What information did Kelvin not have to account for his error?

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

Which of the following nuclear equations correctly describes alpha emission?

Why are smaller nuclei such as carbon-14 often radioactive? (carbon-12 is the most common and most stable form of carbon.)

Which of the following statements about fission is true?

Which type of radiation is being emitted in the following incomplete nuclear equation? Po → Pb + ??

Which of the following is a major advantage of nuclear-fission-based power plants?

If three samples have the half-lives listed below, which is the most radioactive?

What is a half-life?

Uranium-235 releases an average of 2.5 neutrons per fission, while plutonium-239 releases an average of 2.7 neutrons per fission. Which of these elements might you therefore expect to have the smaller critical mass?

During transmutation ________.

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

The strong nuclear force is very sensitive to ________.

Complete the following nuclear equation: Tl → Pb + ??

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

How Atoms Bond

How Molecules Mix

How Water Behaves

How Chemicals React

Acids and Bases in Our Environment

Oxidations and Reductions Charge the World

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

Filters

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