Question 1

The decay constant of a radioactive nuclide is 3.1 x  10−310 ^{- 3}10−3   s−1\mathrm { s } ^ { - 1 }s−1  At a given instant,the activity of a specimen of the nuclide is 70 kBq.How much later has the activity declined to 10 kBq?

Accepted Answer

A)  630 s
B)  690 s
C)  750 s
D)  820 s
E)  880 s F) B) and C)
G) D) and E)

Question 2

A sample containing 4.0 × 1018 atoms of a radioactive isotope decays with a half-life of 2.3 years.How many undecayed atoms are left after 3.7 years?

Accepted Answer

A)  2.5 × 1018
B)  1.7 × 1018
C)  1.3 × 1018
D)  1.1 × 1018E) B) and D)
F) C) and D)

Question 3

A summary of the nuclear reactions that power our sun is 4p → 4He + 2e-,with masses of 938.272 MeV/c2 for a proton,3727.38 MeV/c2 for the helium nucleus,and 0.511 MeV/c2 for each electron.How much energy is released by each of these reactions?

Accepted Answer

A)  24.69 MeV
B)  28.3 MeV
C)  2790.13 MeV
D)  279.01 MeVE) All of the above
F) A) and D)

Question 4

Suppose that starting with $^{227}
_{89}$ ,the following sequence of decays occurs: first an alpha decay,then a beta-minus decay,and finally another alpha decay.What isotope is left after each one of the decays?

Accepted Answer

None...

Question 5

The maximum permissible workday dose for occupational exposure to radiation is 11 mrem.A 77-kg laboratory technician absorbs 2.3 mJ of 0.5-MeV gamma rays in a work day.The relative biological effectiveness (RBE) for gamma rays is 1.00.What is the number of gamma-ray photons absorbed by the technician in a workday?

Accepted Answer

A)  3 × 1010
B)  3 × 109
C)  3 × 108
D)  1 × 109
E)  1 × 108F) B) and C)
G) B) and D)

Question 6

In the nuclear reaction 38
19 K +  11\begin{array} { l } 1 \1\end{array}11​  H → X +  2038{}^{38}_{20}2038​  Ca,what is X?

Accepted Answer

A)  proton
B)  neutron
C)  2H
D)  3H
E)  alpha particle F) A) and B)
G) D) and E)

Question 7

The equation shows a fission reaction: 235 
92 U +  01{}^{1}_{0}01​  n →  4199{}^{99}_{41}4199​  Nb + X + 4  10\begin{array} { l } 1 \0\end{array}10​  n What is the missing term X in the equation?

Accepted Answer

A)    47136Ag^{136}_{47} Ag47136​Ag 
B)    51136Sb^{136} _{51} Sb51136​Sb 
C)    51139Sb^{139}_{51} Sb51139​Sb 
D)    47133Ag^{133}_{47} Ag47133​Ag 
E)    51133Sb^{133}_{51} Sb51133​SbF) B) and D)
G) A) and E)

Question 8

The half-life of a radioactive material is 4.5 days.How many days are required for a sample,with an initial activity of 1.0 × 105 Bq,to decay to an activity of 100 Bq?

Accepted Answer

A)  45 days
B)  36 days
C)  54 days
D)  31 daysE) A) and B)
F) A) and C)

Question 9

Scandium  2143{}^{43}_{21}2143​  Sc decays by emitting a positron.What isotope is the product of this decay?

Accepted Answer

A)    2143{}^{43}_{21}2143​  Sc
B)    2145{}^{45}_{21}2145​  Sc
C)    2044{}^{44}_{20}2044​  Ca
D)    2143{}^{43}_{21}2143​  Ca
E)    2244{}^{44}_{22}2244​  Ti F) A) and D)
G) A) and E)

Question 10

How long would it take 4.00 × 1020 atoms to decay to 1.00 × 1019 atoms if their half-life was 14.7 years?

Accepted Answer

A)  29.4 years
B)  58.8 years
C)  78.2 years
D)  147 yearsE) A) and B)
F) A) and C)

Question 11

When a β- particle is emitted from an unstable nucleus,the atomic 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 E)
G) A) and C)

Question 12

An archaeologist finds the 14C in a sample of  2.10 g2.10 \mathrm {~g}2.10 g  of material to be decaying at 107 Bq.A modern  1.00−g1.00 - \mathrm { g }1.00−g  sample of the same material decays at 151 Bq,and assume this rate has also held in the past.The half-life of 14C is 5730 years.How old is the sample?

Accepted Answer

A)  8980 years
B)  6230 years
C)  17,000 years
D)  8530 years E) B) and C)
F) A) and B)

Question 13

The decay constant of a radioactive isotope is 1.60 × 10-3 s-1.At a given instant,the number of atoms of the radioactive isotope is 1.85 × 1012.How many atoms of the isotope remain after a time interval of 30.0 minutes?

Accepted Answer

A)  1.04 × 1011
B)  1.14 × 1011
C)  1.26 × 1011
D)  1.38 × 1011
E)  1.52 × 1011F) None of the above
G) D) and E)

Question 14

The stability of  1736{}^{36}_{17}1736​  Cl with respect to alpha,beta-plus and beta-minus decay is to be determined.The following atomic masses are known:  24{}^{4}_{2}24​  He: 4.002603 u  3215\begin{array} { l } 32 \15\end{array}3215​  P: 31.973907 u  1636{}^{36}_{16}1636​  S: 35.967081 u  1736{}^{36}_{17}1736​  Cl: 35.968307 u  3818\begin{array} { l } 38 \18\end{array}3818​  Ar: 35.967546 u The  1736{}^{36}_{17}1736​  Cl nucleus is

Accepted Answer

A)  not subject to alpha, beta-plus or beta-minus decay.
B)  subject to alpha decay only.
C)  subject to beta-plus decay only.
D)  subject to beta-minus decay only.
E)  subject to beta-plus or beta-minus decay, but not to alpha decay. F) None of the above
G) D) and E)

Question 15

A carbon-14 nucleus decays to a nitrogen-14 nucleus by beta-minus decay.How much energy (in MeV) is released if carbon-14 has a mass of 14.003242 u and nitrogen-14 has a mass of 14.003074 u? (1 u = 931.5 MeV/c2)

Accepted Answer

A)  0.0156 MeV
B)  0.156 MeV
C)  1.56 MeV
D)  15.6 MeVE) A) and D)
F) A) and C)

Question 16

Suppose that in a certain collection of nuclei there were initially 1024 billion nuclei,and 20.0 minutes later there was only 1.00 billion nuclei left,the others having decayed.On the basis of this information,how many nuclei would you estimate decayed in the first 6.00 minutes?

Accepted Answer

The answer of Suppose that in a certain collection of...

Question 17

What are the mass number A and the charge (in units of e)for each of the following particles or rays?
(a)beta-plus
(b)beta-minus
(c)gamma ray

Accepted Answer

(a)0,1
(b...

Question 18

Determine the missing product X in the following nuclear reaction: $\begin{array} { c } 
16 \
8
\end{array}$ O + neutron → X + alpha particle

Accepted Answer

The answer of Determine the missing product X in the...

Question 19

A person receives an absorbed dose of protons of 20 millirads.The RBE of protons is 5.What is this person's equivalent dose in rem?

Accepted Answer

A)  4 millirem
B)  15 millirem
C)  20 millirem
D)  25 millirem
E)  100 milliremF) A) and E)
G) A) and B)

Question 20

Time (days)  026111930 Counts per  Minute 1000899726556356200\begin{array} { | l | c | c | c | c | c | c | } \hline 	ext { Time (days)  } & 0 & 2 & 6 & 11 & 19 & 30 \\hline 	ext { Counts per } & & & & & & \	ext { Minute } & 1000 & 899 & 726 & 556 & 356 & 200 \\hline\end{array} Time (days)   Counts per  Minute ​01000​2899​6726​11556​19356​30200​​  
In a laboratory accident,a work area is contaminated with radioactive material.Health physicists monitor the area during a 30-day period and obtain the data shown in the table.The accident occurred at time t = 0 days.They determine that it will not be safe for workers to enter the area until the radioactivity level has dropped to 16 counts per minute.Of the choices listed,which one is the earliest time after the accident that workers could safely return?

Accepted Answer

A)  77 days
B)  90 days
C)  102 days
D)  65 days
E)  48 days F) A) and E)
G) C) and E)

Exam 29: Nuclear Physics

Scandium ${}^{43}_{21}$ Sc decays by emitting a positron.What isotope is the product of this decay?

Correct Answer
verified

A summary of the nuclear reactions that power our sun is 4p → ⁴He + 2e^-,with masses of 938.272 MeV/c² for a proton,3727.38 MeV/c² for the helium nucleus,and 0.511 MeV/c² for each electron.How much energy is released by each of these reactions?

Correct Answer
verified

The equation shows a fission reaction: 235 92 U + ${}^{1}_{0}$ n → ${}^{99}_{41}$ Nb + X + 4 $\begin{array} { l } 1 \\0\end{array}$ n What is the missing term X in the equation?

Correct Answer
verified

Suppose that in a certain collection of nuclei there were initially 1024 billion nuclei,and 20.0 minutes later there was only 1.00 billion nuclei left,the others having decayed.On the basis of this information,how many nuclei would you estimate decayed in the first 6.00 minutes?

Correct Answer
verified

How long would it take 4.00 × 10²⁰ atoms to decay to 1.00 × 10¹⁹ atoms if their half-life was 14.7 years?

Correct Answer
verified

The half-life of a radioactive material is 4.5 days.How many days are required for a sample,with an initial activity of 1.0 × 10⁵ Bq,to decay to an activity of 100 Bq?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

An archaeologist finds the ¹⁴C in a sample of $2.10 \mathrm {~g}$ of material to be decaying at 107 Bq.A modern $1.00 - \mathrm { g }$ sample of the same material decays at 151 Bq,and assume this rate has also held in the past.The half-life of ¹⁴C is 5730 years.How old is the sample?

Correct Answer
verified

Determine the missing product X in the following nuclear reaction: $\begin{array} { c } 16 \\8\end{array}$ O + neutron → X + alpha particle

Correct Answer
verified

What are the mass number A and the charge (in units of e)for each of the following particles or rays? (a)beta-plus (b)beta-minus (c)gamma ray

Correct Answer
verified
(a)0,1
(b...
View Answer

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

Correct Answer
verified

The decay constant of a radioactive isotope is 1.60 × 10^-3 s^-1.At a given instant,the number of atoms of the radioactive isotope is 1.85 × 10¹².How many atoms of the isotope remain after a time interval of 30.0 minutes?

Correct Answer
verified

A carbon-14 nucleus decays to a nitrogen-14 nucleus by beta-minus decay.How much energy (in MeV) is released if carbon-14 has a mass of 14.003242 u and nitrogen-14 has a mass of 14.003074 u? (1 u = 931.5 MeV/c²)

Correct Answer
verified

A sample containing 4.0 × 10¹⁸ atoms of a radioactive isotope decays with a half-life of 2.3 years.How many undecayed atoms are left after 3.7 years?

Correct Answer
verified

Correct Answer
verified

Suppose that starting with $^{227}_{89}$ ,the following sequence of decays occurs: first an alpha decay,then a beta-minus decay,and finally another alpha decay.What isotope is left after each one of the decays?

Correct Answer
verified
None...
View Answer

In the nuclear reaction 38 19 K + $\begin{array} { l } 1 \\1\end{array}$ H → X + ${}^{38}_{20}$ Ca,what is X?

Correct Answer
verified

The decay constant of a radioactive nuclide is 3.1 x $10 ^{- 3}$ $\mathrm { s } ^ { - 1 }$ At a given instant,the activity of a specimen of the nuclide is 70 kBq.How much later has the activity declined to 10 kBq?

Correct Answer
verified

A person receives an absorbed dose of protons of 20 millirads.The RBE of protons is 5.What is this person's equivalent dose in rem?

Correct Answer
verified

Exam 29: Nuclear Physics

Scandium 2143{}^{43}_{21}2143​ Sc decays by emitting a positron.What isotope is the product of this decay?

Correct AnswerverifiedShow Answer

A summary of the nuclear reactions that power our sun is 4p → 4He + 2e-,with masses of 938.272 MeV/c2 for a proton,3727.38 MeV/c2 for the helium nucleus,and 0.511 MeV/c2 for each electron.How much energy is released by each of these reactions?

Correct AnswerverifiedShow Answer

The equation shows a fission reaction: 235 92 U + 01{}^{1}_{0}01​ n → 4199{}^{99}_{41}4199​ Nb + X + 4 10\begin{array} { l } 1 \\0\end{array}10​ n What is the missing term X in the equation?

Correct AnswerverifiedShow Answer

Suppose that in a certain collection of nuclei there were initially 1024 billion nuclei,and 20.0 minutes later there was only 1.00 billion nuclei left,the others having decayed.On the basis of this information,how many nuclei would you estimate decayed in the first 6.00 minutes?

Correct AnswerverifiedShow Answer

How long would it take 4.00 × 1020 atoms to decay to 1.00 × 1019 atoms if their half-life was 14.7 years?

Correct AnswerverifiedShow Answer

The half-life of a radioactive material is 4.5 days.How many days are required for a sample,with an initial activity of 1.0 × 105 Bq,to decay to an activity of 100 Bq?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Determine the missing product X in the following nuclear reaction: 168\begin{array} { c } 16 \\8\end{array}168​ O + neutron → X + alpha particle

Correct AnswerverifiedShow Answer

What are the mass number A and the charge (in units of e)for each of the following particles or rays? (a)beta-plus (b)beta-minus (c)gamma ray

Correct Answerverified(a)0,1 (b...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

The decay constant of a radioactive isotope is 1.60 × 10-3 s-1.At a given instant,the number of atoms of the radioactive isotope is 1.85 × 1012.How many atoms of the isotope remain after a time interval of 30.0 minutes?

Correct AnswerverifiedShow Answer

A carbon-14 nucleus decays to a nitrogen-14 nucleus by beta-minus decay.How much energy (in MeV) is released if carbon-14 has a mass of 14.003242 u and nitrogen-14 has a mass of 14.003074 u? (1 u = 931.5 MeV/c2)

Correct AnswerverifiedShow Answer

A sample containing 4.0 × 1018 atoms of a radioactive isotope decays with a half-life of 2.3 years.How many undecayed atoms are left after 3.7 years?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Suppose that starting with 89227^{227}_{89}89227​ ,the following sequence of decays occurs: first an alpha decay,then a beta-minus decay,and finally another alpha decay.What isotope is left after each one of the decays?

Correct AnswerverifiedNone...View AnswerShow Answer

In the nuclear reaction 38 19 K + 11\begin{array} { l } 1 \\1\end{array}11​ H → X + 2038{}^{38}_{20}2038​ Ca,what is X?

Correct AnswerverifiedShow Answer

The decay constant of a radioactive nuclide is 3.1 x 10−310 ^{- 3}10−3 s−1\mathrm { s } ^ { - 1 }s−1 At a given instant,the activity of a specimen of the nuclide is 70 kBq.How much later has the activity declined to 10 kBq?

Correct AnswerverifiedShow Answer

A person receives an absorbed dose of protons of 20 millirads.The RBE of protons is 5.What is this person's equivalent dose in rem?

Correct AnswerverifiedShow Answer

Scandium ${}^{43}_{21}$ Sc decays by emitting a positron.What isotope is the product of this decay?

Correct Answer
verified

A summary of the nuclear reactions that power our sun is 4p → ⁴He + 2e^-,with masses of 938.272 MeV/c² for a proton,3727.38 MeV/c² for the helium nucleus,and 0.511 MeV/c² for each electron.How much energy is released by each of these reactions?

Correct Answer
verified

The equation shows a fission reaction: 235 92 U + ${}^{1}_{0}$ n → ${}^{99}_{41}$ Nb + X + 4 $\begin{array} { l } 1 \\0\end{array}$ n What is the missing term X in the equation?

Correct Answer
verified

Correct Answer
verified

How long would it take 4.00 × 10²⁰ atoms to decay to 1.00 × 10¹⁹ atoms if their half-life was 14.7 years?

Correct Answer
verified

The half-life of a radioactive material is 4.5 days.How many days are required for a sample,with an initial activity of 1.0 × 10⁵ Bq,to decay to an activity of 100 Bq?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Determine the missing product X in the following nuclear reaction: $\begin{array} { c } 16 \\8\end{array}$ O + neutron → X + alpha particle

Correct Answer
verified

Correct Answer
verified
(a)0,1
(b...
View Answer

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

Correct Answer
verified

The decay constant of a radioactive isotope is 1.60 × 10^-3 s^-1.At a given instant,the number of atoms of the radioactive isotope is 1.85 × 10¹².How many atoms of the isotope remain after a time interval of 30.0 minutes?

Correct Answer
verified

A carbon-14 nucleus decays to a nitrogen-14 nucleus by beta-minus decay.How much energy (in MeV) is released if carbon-14 has a mass of 14.003242 u and nitrogen-14 has a mass of 14.003074 u? (1 u = 931.5 MeV/c²)

Correct Answer
verified

A sample containing 4.0 × 10¹⁸ atoms of a radioactive isotope decays with a half-life of 2.3 years.How many undecayed atoms are left after 3.7 years?

Correct Answer
verified

Correct Answer
verified

Suppose that starting with $^{227}_{89}$ ,the following sequence of decays occurs: first an alpha decay,then a beta-minus decay,and finally another alpha decay.What isotope is left after each one of the decays?

Correct Answer
verified
None...
View Answer

In the nuclear reaction 38 19 K + $\begin{array} { l } 1 \\1\end{array}$ H → X + ${}^{38}_{20}$ Ca,what is X?

Correct Answer
verified

The decay constant of a radioactive nuclide is 3.1 x $10 ^{- 3}$ $\mathrm { s } ^ { - 1 }$ At a given instant,the activity of a specimen of the nuclide is 70 kBq.How much later has the activity declined to 10 kBq?

Correct Answer
verified

Correct Answer
verified