The decay rate of an isotope is initially R0,but after one half-life has gone by,the rate is R0/2.At the end of the NEXT half-life,what will the decay rate be?

A) 0 B) R0/16 C) R0/e D) R0/4 E) R0/e2 A) 0 B) R0/16 C) R0/e D) R0/4 E) R0/e2

Exam 42: Nuclear Physics

The radioactive nuclei ⁶⁰Co is widely used in medical applications.It undergoes beta decay,and the total energy of the decay process is 2.82 MeV per decay event.The half-life of this nucleus is 272 days.Suppose that a patient is given a dose of 6.9 µCi of ⁶⁰Co.If all of this material decayed while in the patient's body,what would be the total energy deposited there? (1 Ci = 3.70 × 10¹⁰ decays/s)

(Multiple Choice)

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Question 41

A certain substance has a half-life of 5.0 hours.How many nuclei of the substance are required to give an initial activity of 6.0 μCi? 1 Ci = 3.7 × Bq.

(Multiple Choice)

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Question 42

Modern nuclear bomb tests have created an extra high level of ¹⁴C in our atmosphere.Suppose that future archaeologists date samples from our era,but do not know about this testing.Will their dates be too young,too old,or still correct? If correct they are correct,why?

(Multiple Choice)

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Question 43

The maximum permissible workday dose for occupational exposure to radiation is 26 mrem.A 55-kg laboratory technician absorbs 3.3 mJ of 0.40-MeV gamma rays in a workday.The relative biological efficiency (RBE)for gamma rays is 1.00.What is the ratio of the equivalent dosage received by the technician to the maximum permissible equivalent dosage?

(Multiple Choice)

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Question 44

The half-life of cobalt-60 is 5.3 years,while that of strontium-90 is 28 years.Suppose you have a sample of each,such that they initially contain equal numbers of atoms of these nuclides.How will the activities (number of decays per second)of the samples compare?

(Multiple Choice)

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Question 45

The half-life of cobalt-60 is 5.3 years,while that of strontium-90 is 28 years.Suppose that samples of cobalt-60 and strontium-90 are such that they initially have the same activity (number of decays per second).What is true about the initial numbers of cobalt-60 and strontium-90 nuclei in these samples?

(Multiple Choice)

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Question 46

If a nucleus decays by β⁺ decay to a daughter nucleus,which of the following statements about this decay are correct? (There may be more than one correct choice.)

(Multiple Choice)

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Question 47

A hospital patient has been given some ¹³¹I (half-life = 8.04 d)which decays at 4.2 times the acceptable level for exposure to the general public.How long must the patient wait for the decay rate to reach the acceptable level? Assume that the material merely decays and is not excreted by the body.

(Multiple Choice)

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Question 48

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

(Multiple Choice)

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Question 49

A radioactive atom has 98 protons and 249 nucleons.If it undergoes alpha decay,what are the number of protons and nucleons,respectively,in the daughter nucleus?

(Multiple Choice)

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Question 50

Plutonium-239 decays into uranium-235 plus an alpha particle.The energy released in the process is 5.24 MeV.Given the following mass values He: 4.002603 u U: 235.043924 u what is the mass of Pu in atomic mass units? (1 u = 931.494 MeV/c²)

(Multiple Choice)

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Question 51

The decay rate of an isotope is initially R₀,but after one half-life has gone by,the rate is R₀/2.At the end of the NEXT half-life,what will the decay rate be?

(Multiple Choice)

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Question 52

The iron nucleus has the greatest binding energy of any nucleus.

(True/False)

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Question 53

Scandium, Sc,decays by emitting a positron.What is the nuclide that is the product of the decay?

(Multiple Choice)

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Question 54

A radioactive isotope decays by β^- emission with a half-life of 1.0 min.During the first 1.0 min,a particular sample emits 1000 β^- particles.During the next 1.0 min,the number of β^- particles this sample will emit will be closest to

(Multiple Choice)

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Question 55

A 70-kg laboratory technician absorbs 2.9 mJ of 0.50-MeV gamma rays in a workday.How many gamma-ray photons does the technician absorb in a workday?

(Multiple Choice)

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Question 56

The unstable isotope ²³⁴Th decays by β emission with a half-life of 24.5 days.The initial decay rate of the sample was 9.9 × 10¹³ Bq.(1 u = 1.6605 × 10^-27 kg) (a)What mass of ²³⁴Th was initially present? (b)What is the decay rate after 68 days?

(Short Answer)

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Question 57

What mass of ¹⁴C (having a half-life of 5730 years)do you need to provide a decay rate of 280.0 Bq? (1 u = 1.6605 × 10^-27 kg)

(Multiple Choice)

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Question 58

The neutral deuterium atom, H,has a mass of 2.014102 u; a neutral hydrogen atom has a mass of 1.007825 u; a neutron has a mass of 1.008665 u; and a proton has a mass of 1.007277 u.What is the binding energy of the H nucleus? (1 u = 931.494 MeV/c²)

(Multiple Choice)

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Question 59

Which of the following statements about β⁺ decay are correct? (There may be more than one correct choice.)During β⁺ decay

(Multiple Choice)

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Question 60

Showing 41 - 60 of 64

Exam 42: Nuclear Physics

A certain substance has a half-life of 5.0 hours.How many nuclei of the substance are required to give an initial activity of 6.0 μCi? 1 Ci = 3.7 × Bq.

Modern nuclear bomb tests have created an extra high level of 14C in our atmosphere.Suppose that future archaeologists date samples from our era,but do not know about this testing.Will their dates be too young,too old,or still correct? If correct they are correct,why?

The half-life of cobalt-60 is 5.3 years,while that of strontium-90 is 28 years.Suppose you have a sample of each,such that they initially contain equal numbers of atoms of these nuclides.How will the activities (number of decays per second)of the samples compare?

If a nucleus decays by β+ decay to a daughter nucleus,which of the following statements about this decay are correct? (There may be more than one correct choice.)

A hospital patient has been given some 131I (half-life = 8.04 d)which decays at 4.2 times the acceptable level for exposure to the general public.How long must the patient wait for the decay rate to reach the acceptable level? Assume that the material merely decays and is not excreted by the body.

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

A radioactive atom has 98 protons and 249 nucleons.If it undergoes alpha decay,what are the number of protons and nucleons,respectively,in the daughter nucleus?

Plutonium-239 decays into uranium-235 plus an alpha particle.The energy released in the process is 5.24 MeV.Given the following mass values He: 4.002603 u U: 235.043924 u what is the mass of Pu in atomic mass units? (1 u = 931.494 MeV/c2)

The decay rate of an isotope is initially R0,but after one half-life has gone by,the rate is R0/2.At the end of the NEXT half-life,what will the decay rate be?

The iron nucleus has the greatest binding energy of any nucleus.

Scandium, Sc,decays by emitting a positron.What is the nuclide that is the product of the decay?

A radioactive isotope decays by β- emission with a half-life of 1.0 min.During the first 1.0 min,a particular sample emits 1000 β- particles.During the next 1.0 min,the number of β- particles this sample will emit will be closest to

A 70-kg laboratory technician absorbs 2.9 mJ of 0.50-MeV gamma rays in a workday.How many gamma-ray photons does the technician absorb in a workday?

The unstable isotope 234Th decays by β emission with a half-life of 24.5 days.The initial decay rate of the sample was 9.9 × 1013 Bq.(1 u = 1.6605 × 10-27 kg) (a)What mass of 234Th was initially present? (b)What is the decay rate after 68 days?

What mass of 14C (having a half-life of 5730 years)do you need to provide a decay rate of 280.0 Bq? (1 u = 1.6605 × 10-27 kg)

The neutral deuterium atom, H,has a mass of 2.014102 u; a neutral hydrogen atom has a mass of 1.007825 u; a neutron has a mass of 1.008665 u; and a proton has a mass of 1.007277 u.What is the binding energy of the H nucleus? (1 u = 931.494 MeV/c2)

Which of the following statements about β+ decay are correct? (There may be more than one correct choice.)During β+ decay

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Modern nuclear bomb tests have created an extra high level of ¹⁴C in our atmosphere.Suppose that future archaeologists date samples from our era,but do not know about this testing.Will their dates be too young,too old,or still correct? If correct they are correct,why?

If a nucleus decays by β⁺ decay to a daughter nucleus,which of the following statements about this decay are correct? (There may be more than one correct choice.)

Plutonium-239 decays into uranium-235 plus an alpha particle.The energy released in the process is 5.24 MeV.Given the following mass values He: 4.002603 u U: 235.043924 u what is the mass of Pu in atomic mass units? (1 u = 931.494 MeV/c²)

The decay rate of an isotope is initially R₀,but after one half-life has gone by,the rate is R₀/2.At the end of the NEXT half-life,what will the decay rate be?

A radioactive isotope decays by β^- emission with a half-life of 1.0 min.During the first 1.0 min,a particular sample emits 1000 β^- particles.During the next 1.0 min,the number of β^- particles this sample will emit will be closest to

The unstable isotope ²³⁴Th decays by β emission with a half-life of 24.5 days.The initial decay rate of the sample was 9.9 × 10¹³ Bq.(1 u = 1.6605 × 10^-27 kg) (a)What mass of ²³⁴Th was initially present? (b)What is the decay rate after 68 days?

What mass of ¹⁴C (having a half-life of 5730 years)do you need to provide a decay rate of 280.0 Bq? (1 u = 1.6605 × 10^-27 kg)

The neutral deuterium atom, H,has a mass of 2.014102 u; a neutral hydrogen atom has a mass of 1.007825 u; a neutron has a mass of 1.008665 u; and a proton has a mass of 1.007277 u.What is the binding energy of the H nucleus? (1 u = 931.494 MeV/c²)

Which of the following statements about β⁺ decay are correct? (There may be more than one correct choice.)During β⁺ decay