Question 1

Polonium-216 decays to lead-212 by emitting what kind of nuclear radiation?

Accepted Answer

A)  alpha
B)  beta-minus
C)  beta-plus
D)  gamma
E)  x-rays.F) B) and E)
G) All of the above

Question 2

A gamma ray is also known as

Accepted Answer

A)  an electron.
B)  a positron.
C)  a helium nucleus.
D)  a high-energy photon.E) A) and B)
F) A) and C)

Question 3

When a β- particle is emitted from an unstable nucleus,the atomic mass number of the nucleus

Accepted Answer

A)  increases by 1.
B)  decreases by 1.
C)  increases by 2.
D)  decreases by 2.
E)  does not change.F) A) and B)
G) A) and C)

Question 4

Two radioactive isotopes,X and Y,both decay to stable products.The half-life of X is about a day,while that of Y is about a week.Suppose a radioactive sample consists of a mixture of these two nuclides.If the mixture is such that the activities arising from X and Y are initially equal,then a few days later the activity of the sample will be due

Accepted Answer

A)  predominantly to Y.
B)  predominantly to X.
C)  entirely to Y.
D)  to X and Y equally.E) A) and B)
F) A) and C)

Question 5

The atom  87223Fr^{223}_{87} Fr87223​Fr  decays to  88223{}^{223}_{88}88223​  Ra by emitting what kind of nuclear radiation?

Accepted Answer

A)  alpha
B)  beta-minus
C)  beta-plus
D)  gamma
E)  x-rays. F) A) and E)
G) B) and C)

Question 6

Given that the half-life for radium-226 is 1600 y,how long is the "quarter-life" (that is,the time for the radiation to decay to one-fourth of its initial level)?

Accepted Answer

The answer of Given that the half-life for radium-226 is...

Question 7

A radioactive sample has a half-life of 10 min.What fraction of the sample is left after 40 min?

Accepted Answer

A)  1/2
B)  1/4
C)  1/8
D)  1/16E) None of the above
F) A) and D)

Question 8

The half-life of radon-222 is 3.83 d.If a sample of radon initially contains 6.00 × 108 radon atoms,how many of them are left after 10.0 d?

Accepted Answer

A)  9.82 × 107
B)  7.67 × 107
C)  8.34 × 108
D)  7.29 × 108
E)  8.56 × 108F) A) and B)
G) None of the above

Question 9

The half-life of cobalt-60 is 5.3 years,while that of strontium-90 is about 29 years.Suppose you have samples of both isotopes,and that they initially contain equal numbers of atoms of these isotopes.How will the activities (number of decays per second) of the samples compare?

Accepted Answer

A)  The activity of the cobalt-60 sample will be greater.
B)  The activities cannot be compared without more information.
C)  The activities will be equal.
D)  The activity of the strontium-90 sample will be greater.E) A) and D)
F) None of the above

Question 10

An oxygen-15 nucleus,  815{}^{15}_{8}815​  O,decays to another atomic nucleus by emitting a β+ ray.What is the other atomic nucleus?

Accepted Answer

A)    715{}^{15}_{7}715​  N
B)    168\begin{array} { c } 16 \8\end{array}168​  F
C)    615{}^{15}_{6}615​  C
D)    814{}^{14}_{8}814​  C
E)    717{}^{17}_{7}717​  N F) A) and B)
G) B) and E)

Question 11

The atom 40K decays radioactively to the gas 40Ar.An ancient rock is found to contain enough 40Ar gas to indicate that 77.0% of the 40K in the rock has decayed to 40Ar since the rock solidified.(Any previous argon would have boiled out of liquid rock.) How long ago did the rock solidify? The half-life of 40K is 1.25 billion years.

Accepted Answer

A)  2.65 billion years
B)  0.471 billion years
C)  1.80 billion years
D)  0.324 billion yearsE) B) and D)
F) All of the above

Question 12

Suppose the half-life of an isotope is 2 days.You purchase 10 grams of the isotope,but it was produced in a laboratory 4 days before it was delivered to you.How much of this isotope will you have 3 days after it was delivered to you?

Accepted Answer

A)  more than 2.5 grams but less than 5 grams
B)  2.5 grams
C)  more than 1.25 grams but less than 2.5 grams
D)  1.25 grams
E)  less than 1.25 gramsF) A) and B)
G) A) and E)

Question 13

A 1.0-mol sample of an isotope is decaying with a half-life of 28 y.After 61 y,how many moles of this isotope are left and what is its activity in Bq?

Accepted Answer

0.22 mol,1...

Question 14

When a neutron collides with a uranium-235 nucleus it can induce a variety of fission reactions.One such reaction is  92235U^{235} _{92} U92235​U  +  01{}^{1}_{0}01​  n →  54140Xe^{140}_{54} Xe54140​Xe  +  3894{}^{94}_{38}3894​  Sr + 2  01{}^{1}_{0}01​  n The following mass values are known: 
 54140Xe^{140}_{54} Xe54140​Xe : 139.921620 u

3894{}^{94}_{38}3894​  Sr: 93.915367 u

92235U^{235} _{92} U92235​U : 235.043924 u  01n{}\^{1}_{0}n01​n  : 1.008665 u
How much energy is released in this reaction? (1 u = 931.5 MeV/c2)

Accepted Answer

A)  185 MeV
B)  202 MeV
C)  32.6 MeV
D)  65.7 MeV
E)  98.6 MeV F) B) and D)
G) All of the above

Question 15

The symbol for a certain isotope of polonium is  84214Po^{214}_{84} Po84214​Po .How many neutrons are there in the nucleus of this isotope?

Accepted Answer

A)  84
B)  130
C)  214
D)  298
E)  314 F) A) and C)
G) B) and D)

Question 16

Plutonium has a half life of 2.4 × 104 years.How long does it take for 99.0% of the plutonium to decay?

Accepted Answer

A)  1.6 × 102 y
B)  1.6 × 103 y
C)  1.6 × 104 y
D)  1.6 × 105 y
E)  1.6 × 106 yF) C) and D)
G) B) and C)

Question 17

When a neutron collides with a uranium-235 nucleus it can induce a variety of fission reactions.One such reaction is  92235U^{235} _{92} U92235​U  +  01{}^{1}_{0}01​  n →  54140Xe^{140}_{54} Xe54140​Xe  +  3894{}^{94}_{38}3894​  Sr + 2  01{}^{1}_{0}01​  n The following mass values are known:   54140Xe^{140}_{54} Xe54140​Xe : 139.921620 u  3894{}^{94}_{38}3894​  Sr: 93.915367 u   92235U^{235} _{92} U92235​U : 235.043924 u  01{}^{1}_{0}01​  n: 1.008665 u
What mass of uranium is needed to produce a 10-kiloton yield? (1 u = 931.5 MeV/c2 = 1.66054 × 10-27 kg,1-kiloton yield = 5.0 × 1012 J)

Accepted Answer

A)  0.57 kg
B)  0.66 kg
C)  6.58 kg
D)  3.85 kg
E)  1.10 kg F) B) and C)
G) A) and E)

Question 18

Rutherfordium-261 has a half-life of 1.08 min.How long will it take for a sample of rutherfordium to lose one-third of its nuclei?

Accepted Answer

A)  1.02 min
B)  1.62 min
C)  0.632 min
D)  2.70 min
E)  3.24 minF) B) and D)
G) A) and D)

Question 19

A hospital patient has been given a sample of 131I ,which has a half-life of 8.04 days.This sample is decaying at 5.9 times the acceptable level for exposure to the general public.How long must the patient wait for the decay rate of the sample to reach the acceptable level?

Accepted Answer

A)  21 days
B)  14 days
C)  9.9 days
D)  8.9 daysE) A) and D)
F) A) and B)

Question 20

The half-life of cobalt-60 is 5.3 years,while that of strontium-90 is about 29 years.Suppose you have samples of both isotopes,and that they initially have the same activity (number of decays per second) .What must be true of the numbers of cobalt-60 and strontium-90 nuclei in these samples?

Accepted Answer

A)  There are more strontium-90 than cobalt-60 nuclei.
B)  There are equal numbers of cobalt-60 and strontium-90 nuclei.
C)  There are more cobalt-60 than strontium-90 nuclei.
D)  It is not possible to compare numbers of nuclei without knowing the masses of the samples.E) A) and B)
F) All of the above

Exam 29: Nuclear Physics

A hospital patient has been given a sample of ¹³¹I ,which has a half-life of 8.04 days.This sample is decaying at 5.9 times the acceptable level for exposure to the general public.How long must the patient wait for the decay rate of the sample to reach the acceptable level?

Correct Answer
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Suppose the half-life of an isotope is 2 days.You purchase 10 grams of the isotope,but it was produced in a laboratory 4 days before it was delivered to you.How much of this isotope will you have 3 days after it was delivered to you?

Correct Answer
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Correct Answer
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An oxygen-15 nucleus, ${}^{15}_{8}$ O,decays to another atomic nucleus by emitting a β⁺ ray.What is the other atomic nucleus?

Correct Answer
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Given that the half-life for radium-226 is 1600 y,how long is the "quarter-life" (that is,the time for the radiation to decay to one-fourth of its initial level)?

Correct Answer
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Plutonium has a half life of 2.4 × 10⁴ years.How long does it take for 99.0% of the plutonium to decay?

Correct Answer
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The atom $^{223}_{87} Fr$ decays to ${}^{223}_{88}$ Ra by emitting what kind of nuclear radiation?

Correct Answer
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A radioactive sample has a half-life of 10 min.What fraction of the sample is left after 40 min?

Correct Answer
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A 1.0-mol sample of an isotope is decaying with a half-life of 28 y.After 61 y,how many moles of this isotope are left and what is its activity in Bq?

Correct Answer
verified
0.22 mol,1...
View Answer

Rutherfordium-261 has a half-life of 1.08 min.How long will it take for a sample of rutherfordium to lose one-third of its nuclei?

Correct Answer
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Correct Answer
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Correct Answer
verified

The symbol for a certain isotope of polonium is $^{214}_{84} Po$ .How many neutrons are there in the nucleus of this isotope?

Correct Answer
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The half-life of cobalt-60 is 5.3 years,while that of strontium-90 is about 29 years.Suppose you have samples of both isotopes,and that they initially have the same activity (number of decays per second) .What must be true of the numbers of cobalt-60 and strontium-90 nuclei in these samples?

Correct Answer
verified

Correct Answer
verified

Polonium-216 decays to lead-212 by emitting what kind of nuclear radiation?

Correct Answer
verified

A gamma ray is also known as

Correct Answer
verified

The half-life of cobalt-60 is 5.3 years,while that of strontium-90 is about 29 years.Suppose you have samples of both isotopes,and that they initially contain equal numbers of atoms of these isotopes.How will the activities (number of decays per second) of the samples compare?

Correct Answer
verified

When a β^- particle is emitted from an unstable nucleus,the atomic mass number of the nucleus

Correct Answer
verified

The half-life of radon-222 is 3.83 d.If a sample of radon initially contains 6.00 × 10⁸ radon atoms,how many of them are left after 10.0 d?

Correct Answer
verified

Exam 29: Nuclear Physics

A hospital patient has been given a sample of 131I ,which has a half-life of 8.04 days.This sample is decaying at 5.9 times the acceptable level for exposure to the general public.How long must the patient wait for the decay rate of the sample to reach the acceptable level?

Correct AnswerverifiedShow Answer

Suppose the half-life of an isotope is 2 days.You purchase 10 grams of the isotope,but it was produced in a laboratory 4 days before it was delivered to you.How much of this isotope will you have 3 days after it was delivered to you?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

An oxygen-15 nucleus, 815{}^{15}_{8}815​ O,decays to another atomic nucleus by emitting a β+ ray.What is the other atomic nucleus?

Correct AnswerverifiedShow Answer

Given that the half-life for radium-226 is 1600 y,how long is the "quarter-life" (that is,the time for the radiation to decay to one-fourth of its initial level)?

Correct AnswerverifiedShow Answer

Plutonium has a half life of 2.4 × 104 years.How long does it take for 99.0% of the plutonium to decay?

Correct AnswerverifiedShow Answer

The atom 87223Fr^{223}_{87} Fr87223​Fr decays to 88223{}^{223}_{88}88223​ Ra by emitting what kind of nuclear radiation?

Correct AnswerverifiedShow Answer

A radioactive sample has a half-life of 10 min.What fraction of the sample is left after 40 min?

Correct AnswerverifiedShow Answer

A 1.0-mol sample of an isotope is decaying with a half-life of 28 y.After 61 y,how many moles of this isotope are left and what is its activity in Bq?

Correct Answerverified0.22 mol,1...View AnswerShow Answer

Rutherfordium-261 has a half-life of 1.08 min.How long will it take for a sample of rutherfordium to lose one-third of its nuclei?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The symbol for a certain isotope of polonium is 84214Po^{214}_{84} Po84214​Po .How many neutrons are there in the nucleus of this isotope?

Correct AnswerverifiedShow Answer

The half-life of cobalt-60 is 5.3 years,while that of strontium-90 is about 29 years.Suppose you have samples of both isotopes,and that they initially have the same activity (number of decays per second) .What must be true of the numbers of cobalt-60 and strontium-90 nuclei in these samples?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Polonium-216 decays to lead-212 by emitting what kind of nuclear radiation?

Correct AnswerverifiedShow Answer

A gamma ray is also known as

Correct AnswerverifiedShow Answer

The half-life of cobalt-60 is 5.3 years,while that of strontium-90 is about 29 years.Suppose you have samples of both isotopes,and that they initially contain equal numbers of atoms of these isotopes.How will the activities (number of decays per second) of the samples compare?

Correct AnswerverifiedShow Answer

When a β- particle is emitted from an unstable nucleus,the atomic mass number of the nucleus

Correct AnswerverifiedShow Answer

The half-life of radon-222 is 3.83 d.If a sample of radon initially contains 6.00 × 108 radon atoms,how many of them are left after 10.0 d?

Correct AnswerverifiedShow Answer

A hospital patient has been given a sample of ¹³¹I ,which has a half-life of 8.04 days.This sample is decaying at 5.9 times the acceptable level for exposure to the general public.How long must the patient wait for the decay rate of the sample to reach the acceptable level?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

An oxygen-15 nucleus, ${}^{15}_{8}$ O,decays to another atomic nucleus by emitting a β⁺ ray.What is the other atomic nucleus?

Correct Answer
verified

Correct Answer
verified

Plutonium has a half life of 2.4 × 10⁴ years.How long does it take for 99.0% of the plutonium to decay?

Correct Answer
verified

The atom $^{223}_{87} Fr$ decays to ${}^{223}_{88}$ Ra by emitting what kind of nuclear radiation?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
0.22 mol,1...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

The symbol for a certain isotope of polonium is $^{214}_{84} Po$ .How many neutrons are there in the nucleus of this isotope?

Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

When a β^- particle is emitted from an unstable nucleus,the atomic mass number of the nucleus

Correct Answer
verified

The half-life of radon-222 is 3.83 d.If a sample of radon initially contains 6.00 × 10⁸ radon atoms,how many of them are left after 10.0 d?

Correct Answer
verified