Question 1

${ }_{92}^{235} \mathrm{U}$ (uranium) can decay to ${ }_{82}^{206} \mathrm{~Pb}$ (lead) through an appropriate sequence of alpha and beta decay processes.

Accepted Answer

The answer of ${ }_{92}^{235} \mathrm{U}$ (uranium) can decay to...

Question 2

${ }_{94}^{232} \mathrm{Pu}$ is unstable. Which of the following nuclei might be a possible outcome of a single-step decay process from this nucleus? (Hints: The optimal NIZ ratio for this $A$ is about 1.53. This nucleus has two possible decay outcomes, but perhaps only one is listed. If you are using the back of the book to respond, you can indicate multiple responses by pointing to more than one letter.)

Accepted Answer

The answer of ${ }_{94}^{232} \mathrm{Pu}$ is unstable. Which of...

Question 3

The most important reason that an alpha particle can be stopped by a single sheet of paper while an electron of the same energy might not be stopped by hundreds of sheets of paper is that the alpha particle

Accepted Answer

The answer of The most important reason that an alpha...

Question 4

The main reason that gamma photons are more penetrating than either alpha particles or electrons is that

Accepted Answer

The answer of The main reason that gamma photons are...

Question 5

A positron will travel roughly as far through a given material as an electron with the same energy.

Accepted Answer

A positron and an electron with the same energy will have similar interactions with matter, such as ionization and radiation losses, leading them to travel roughly the same distance through a given material.

Question 6

A radioactive sample's activity $A$ at a given time is directly proportional to the number of nuclei that have already decayed.

Accepted Answer

The activity $A$ of a radioactive sample is directly proportional to the number of undecayed nuclei present at that time, not the number that have already decayed.

Question 7

The amount of ${ }_{18}^{40} \mathrm{Ar}$ is one-ninth the amount of ${ }_{19}^{40} \mathrm{~K}$. If the half-life of the latter is $T$, what is the rock's age?

Accepted Answer

The rock's age is $T$ because the amount of ${ }_{19}^{40} \mathrm{~K}$ has decreased to half its original amount once, which corresponds to one half-life period $T$.

Question 8

The amount of ${ }_{6}^{14} \mathrm{C}$ in a bone is about one-fourth of what one would expect based on the relative abundance of ${ }_{6}^{14} \mathrm{C}$ and ${ }_{6}^{12} \mathrm{C}$. Since the half-life of ${ }_{6}^{14} \mathrm{C}$ is a bit less than $6000 \mathrm{y}$, the bone's age is closest to

Accepted Answer

If the amount of ${ }_{6}^{14} \mathrm{C}$ is one-fourth of the expected amount, it means that two half-lives have passed (since $(1/2)^2 = 1/4$). Given that the half-life of ${ }_{6}^{14} \mathrm{C}$ is about 6000 years, the age of the bone is approximately $2 \times 6000 = 12,000$ years.

Question 9

Combining any two nuclei should release energy, because doing this increases the number of strong inter nuclear bonds between nucleons.

Accepted Answer

Combining any two nuclei does not always release energy. Fusion releases energy when light nuclei combine, but for heavier nuclei, the process requires energy due to the increasing repulsive forces between protons.

Question 10

A nucleus with binding energy $E_{b 1}$ fuses with one having binding energy $E_{b 2}$. The resulting nucleus has binding energy $E_{b 3}$. What is the total energy released in this fusion reaction?

Accepted Answer

The energy released in a fusion reaction is given by the difference between the sum of the binding energies of the initial nuclei and the binding energy of the resulting nucleus. Therefore, the correct formula is $E_{b 3}-E_{b 1}-E_{b 2}$.

Question 11

Nuclei with the highest binding energy per nucleon $e_{b}$ have $Z$ most closely equal to what?

Accepted Answer

Nuclei with the highest binding energy per nucleon are typically around iron (Fe), which has an atomic number $Z$ of 26. This is because iron-56 is one of the most stable nuclei, having the highest binding energy per nucleon.

Question 12

Which of the following nuclei has the greatest binding energy per nucleon?

Accepted Answer

Iron-56 (${ }_{26}^{56} \mathrm{Fe}$) has the greatest binding energy per nucleon, making it the most stable nucleus among the options listed. This is why iron is often found at the core of stars, including the Sun, as a product of fusion processes.

Question 13

A terrorist organization seeking to construct a nuclear bomb would likely be more interested in obtaining ${ }_{92}^{235} \mathrm{U}$ than 94 Pu.

Accepted Answer

${ }_{92}^{235} \mathrm{U}$ (Uranium-235) is easier to use in the construction of a nuclear bomb due to its ability to sustain a nuclear chain reaction with less technical complexity compared to Plutonium (${ }_{94} \mathrm{Pu}$).

Question 14

Exposure to radiation of any kind for long enough will tend to make an object radioactive.

Accepted Answer

Exposure to radiation does not necessarily make an object radioactive. Radioactivity is a property of certain materials that spontaneously emit radiation, and an object becomes radioactive primarily by incorporating radioactive materials into its structure, not merely by being exposed to radiation.

Question 15

The moderator in a fission reactor

Accepted Answer

The moderator in a fission reactor slows down neutrons to make them more effective in sustaining the chain reaction by increasing the probability of these neutrons to cause further fission when they collide with fissile material.

Question 16

Which of the following events is most likely to directly cause a meltdown in a nuclear fission reactor?

Accepted Answer

A meltdown in a nuclear fission reactor is most directly caused by the failure of the cooling system, such as the pumps that circulate water. This leads to overheating and potential meltdown.

Question 17

Fusion power is completely safe and has no radioactive waste disposal problem.

Accepted Answer

Fusion power produces less radioactive waste compared to fission, but it is not completely safe or free from radioactive waste disposal issues. Fusion reactors can produce radioactive waste through the activation of reactor materials by neutron radiation.

Question 18

The fusion reactions used in thermonuclear bombs and fusion power experiments are exactly the same as those used in the sun.

Accepted Answer

The fusion reactions in the Sun primarily involve the proton-proton chain reaction, converting hydrogen into helium. Thermonuclear bombs and fusion power experiments typically use the deuterium-tritium reaction, which is easier to initiate and requires lower temperatures.

Question 19

If a complex number is equal to its own complex conjugate, then the complex number is real.

Accepted Answer

A complex number is equal to its own complex conjugate only if its imaginary part is zero, which means the complex number is a real number.

Question 20

What is -1 expressed as a phase factor?

Accepted Answer

-1 expressed as a phase factor is $e^{i \pi}$, according to Euler's formula $e^{i\theta} = \cos(\theta) + i\sin(\theta)$, where $\theta = \pi$ radians.

Quiz 5: Matter Behaves Like Waves Quantum Physics

${ }_{92}^{235} \mathrm{U}$ (uranium) can decay to ${ }_{82}^{206} \mathrm{~Pb}$ (lead) through an appropriate sequence of alpha and beta decay processes.

The most important reason that an alpha particle can be stopped by a single sheet of paper while an electron of the same energy might not be stopped by hundreds of sheets of paper is that the alpha particle

The main reason that gamma photons are more penetrating than either alpha particles or electrons is that

A positron will travel roughly as far through a given material as an electron with the same energy.

A radioactive sample's activity $A$ at a given time is directly proportional to the number of nuclei that have already decayed.

The amount of ${ }_{18}^{40} \mathrm{Ar}$ is one-ninth the amount of ${ }_{19}^{40} \mathrm{~K}$ . If the half-life of the latter is $T$ , what is the rock's age?

Combining any two nuclei should release energy, because doing this increases the number of strong inter nuclear bonds between nucleons.

A nucleus with binding energy $E_{b 1}$ fuses with one having binding energy $E_{b 2}$ . The resulting nucleus has binding energy $E_{b 3}$ . What is the total energy released in this fusion reaction?

Nuclei with the highest binding energy per nucleon $e_{b}$ have $Z$ most closely equal to what?

Which of the following nuclei has the greatest binding energy per nucleon?

A terrorist organization seeking to construct a nuclear bomb would likely be more interested in obtaining ${ }_{92}^{235} \mathrm{U}$ than 94 Pu.

Exposure to radiation of any kind for long enough will tend to make an object radioactive.

The moderator in a fission reactor

Which of the following events is most likely to directly cause a meltdown in a nuclear fission reactor?

Fusion power is completely safe and has no radioactive waste disposal problem.

The fusion reactions used in thermonuclear bombs and fusion power experiments are exactly the same as those used in the sun.

If a complex number is equal to its own complex conjugate, then the complex number is real.

What is -1 expressed as a phase factor?

Quiz 5: Matter Behaves Like Waves Quantum Physics

92235U{ }_{92}^{235} \mathrm{U}92235​U (uranium) can decay to 82206 Pb{ }_{82}^{206} \mathrm{~Pb}82206​ Pb (lead) through an appropriate sequence of alpha and beta decay processes.

The most important reason that an alpha particle can be stopped by a single sheet of paper while an electron of the same energy might not be stopped by hundreds of sheets of paper is that the alpha particle

The main reason that gamma photons are more penetrating than either alpha particles or electrons is that

A positron will travel roughly as far through a given material as an electron with the same energy.

A radioactive sample's activity AAA at a given time is directly proportional to the number of nuclei that have already decayed.

The amount of 1840Ar{ }_{18}^{40} \mathrm{Ar}1840​Ar is one-ninth the amount of 1940 K{ }_{19}^{40} \mathrm{~K}1940​ K . If the half-life of the latter is TTT , what is the rock's age?

Combining any two nuclei should release energy, because doing this increases the number of strong inter nuclear bonds between nucleons.

A nucleus with binding energy Eb1E_{b 1}Eb1​ fuses with one having binding energy Eb2E_{b 2}Eb2​ . The resulting nucleus has binding energy Eb3E_{b 3}Eb3​ . What is the total energy released in this fusion reaction?

Nuclei with the highest binding energy per nucleon ebe_{b}eb​ have ZZZ most closely equal to what?

Which of the following nuclei has the greatest binding energy per nucleon?

A terrorist organization seeking to construct a nuclear bomb would likely be more interested in obtaining 92235U{ }_{92}^{235} \mathrm{U}92235​U than 94 Pu.

Exposure to radiation of any kind for long enough will tend to make an object radioactive.

The moderator in a fission reactor

Which of the following events is most likely to directly cause a meltdown in a nuclear fission reactor?

Fusion power is completely safe and has no radioactive waste disposal problem.

The fusion reactions used in thermonuclear bombs and fusion power experiments are exactly the same as those used in the sun.

If a complex number is equal to its own complex conjugate, then the complex number is real.

What is -1 expressed as a phase factor?

${ }_{92}^{235} \mathrm{U}$ (uranium) can decay to ${ }_{82}^{206} \mathrm{~Pb}$ (lead) through an appropriate sequence of alpha and beta decay processes.

A radioactive sample's activity $A$ at a given time is directly proportional to the number of nuclei that have already decayed.

The amount of ${ }_{18}^{40} \mathrm{Ar}$ is one-ninth the amount of ${ }_{19}^{40} \mathrm{~K}$ . If the half-life of the latter is $T$ , what is the rock's age?

A nucleus with binding energy $E_{b 1}$ fuses with one having binding energy $E_{b 2}$ . The resulting nucleus has binding energy $E_{b 3}$ . What is the total energy released in this fusion reaction?

Nuclei with the highest binding energy per nucleon $e_{b}$ have $Z$ most closely equal to what?

A terrorist organization seeking to construct a nuclear bomb would likely be more interested in obtaining ${ }_{92}^{235} \mathrm{U}$ than 94 Pu.