Question 1

Write the standard nuclear notation for the following nuclei: hydrogen-2, sulfur-33, and
lead-207.

Accepted Answer

The answer of Write the standard nuclear notation for the...

Question 2

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 3

A beryllium-8 nucleus at rest undergoes double alpha decay as follows:
 48Be→24He+24He{ } _ { 4 } ^ { 8 } \mathrm { Be } \rightarrow { } _ { 2 } ^ { 4 } \mathrm { He } + { } _ { 2 } ^ { 4 } \mathrm { He }48​Be→24​He+24​He 
The known atomic masses are:
 24He:4.002603u{ } _ { 2 } ^ { 4 } \mathrm { He } : \quad 4.002603 \mathrm { u }24​He:4.002603u 
 48Be:8.005305u{ } _ { 4 } ^ { 8 } \mathrm { Be } : \quad 8.005305 \mathrm { u }48​Be:8.005305u 
What is the kinetic energy of each departing alpha particle?  (1u=931.5MeV/c2) \left( 1 \mathrm { u } = 931.5 \mathrm { MeV } / \mathrm { c } ^ { 2 } \right) (1u=931.5MeV/c2)

Accepted Answer

A)    130keV130 \mathrm { keV }130keV 
B)    92keV92 \mathrm { keV }92keV 
C)    180keV180 \mathrm { keV }180keV 
D)    46keV46 \mathrm { keV }46keV 
E)    65keV65 \mathrm { keV }65keVF) A) and B)
G) B) and E)

Question 4

The half-life of cobalt-60 is  5.35.35.3  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 more cobalt-60 than strontium-90 nuclei.
C)   There are equal numbers of cobalt-60 and strontium-90 nuclei.
D)   It is not possible to compare numbers of nuclei without knowing the masses of the samples. E) B) and D)
F) A) and C)

Question 5

The symbol for a certain isotope of strontium is  3890Sr{ } _ { 38 } ^ { 90 } \mathrm { Sr }3890​Sr . What is the mass number of this isotope?

Accepted Answer

A)   128
B)   90
C)   38
D)   88
E)   52 F) All of the above
G) B) and E)

Question 6

When a  β−\beta ^ { - }β− particle is emitted from an unstable nucleus, the atomic mass number of the nucleus

Accepted Answer

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

Question 7

$$\text { The mean life (time constant) of rubidium-86 is } 26.8 \mathrm {~d} \text {. What is its half-life? }$$

Accepted Answer

The answer of \[\text { The mean life (time constant)...

Question 8

If an atomic nucleus containing 64 nucleons has a mass density  ρ\rhoρ , what will be the expected mass density of a nucleus containing 512 nucleons?

Accepted Answer

A)    8ρ8 \rho8ρ 
B)    16ρ16 \rho16ρ 
C)    ρ\rhoρ 
D)    4ρ4 \rho4ρ 
E)    2ρ2 \rho2ρF) D) and E)
G) A) and C)

Question 9

The decay rate of a radioactive sample decreases from $175 \mathrm { kBq }$ to $12.4 \mathrm { kBq }$ in $18.3 \mathrm {~s}$. Wha is the half-life of this sample?

Accepted Answer

The answer of The decay rate of a radioactive sample...

Question 10

The main reason that there is a limit to the size of a stable nucleus is

Accepted Answer

A)   the weakness of the electrostatic force.
B)   the limited range of the gravitational force.
C)   the short range nature of the strong nuclear force.
D)   the weakness of the gravitational force.E) A) and B)
F) All of the above

Question 11

The diameter of an atom is  1.4×10−10 m1.4 	imes 10 ^ { - 10 } \mathrm {~m}1.4×10−10 m  and the diameter of its nucleus is  1.0×10−14 m1.0 	imes 10 ^ { - 14 } \mathrm {~m}1.0×10−14 m . What fraction of the atom's volume is occupied by its nucleus?

Accepted Answer

A)    7.1×10−57.1 	imes 10 ^ { - 5 }7.1×10−5 
B)    5.1×10−95.1 	imes 10 ^ { - 9 }5.1×10−9 
C)    3.6×10−133.6 	imes 10 ^ { - 13 }3.6×10−13 
D)    2.6×10−172.6 	imes 10 ^ { - 17 }2.6×10−17E) B) and C)
F) None of the above

Question 12

A nucleus ${ } _ { M } ^ { N } X$ undergoes one alpha decay followed by 3 beta-minus decays.
(a) What is the resulting nucleus in terms of $\mathrm { M }$ and $\mathrm { N }$ ?
(b) If there had been 3 beta-plus decays instead of the beta-minus decays, what would have been the resulting nucleus in terms of $M$ and $N$ ?

Accepted Answer

The answer of A nucleus \({ } _ { M...

Question 13

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

Accepted Answer

A)   alpha
B)   beta-minus
C)    xxx -rays.
D)   gamma
E)   beta-plus F) None of the above
G) B) and E)

Question 14

Isotope A has a decay constant of  0.723 s−10.723 \mathrm {~s} ^ { - 1 }0.723 s−1  and isotope B has a decay constant of  0.514 s−10.514 \mathrm {~s} ^ { - 1 }0.514 s−1 . Which isotope has a longer half-life?

Accepted Answer

A)   isotope  AAA 
B)   isotope B C) A) and B)
D) undefined

Question 15

Rutherfordium-261 has a half-life of  1.08 min1.08 \mathrm {~min}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 min1.02 \mathrm {~min}1.02 min 
B)    1.62 min1.62 \mathrm {~min}1.62 min 
C)    2.70 min2.70 \mathrm {~min}2.70 min 
D)    0.632 min0.632 \mathrm {~min}0.632 min 
E)    3.24 min3.24 \mathrm {~min}3.24 minF) A) and C)
G) A) and B)

Question 16

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

Accepted Answer

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

Question 17

$$\text { In the radioactive decay equation } { } _ { 92 } ^ { 238 } \rightarrow { } _ { 90 } ^ { 234 } \mathrm { Th } + \mathrm { X } \text {, what is } \mathrm { X } \text { ? }$$

Accepted Answer

The answer of \[\text { In the radioactive decay equation...

Question 18

When an unstable nucleus decays by emitting an alpha particle, the atomic number  Z\mathrm { Z }Z  of the nucleus

Accepted Answer

A)   decreases by 4 .
B)   decreases by 2 .
C)   increases by  4.4 .4. 
D)   increases by 2 .
E)   remains unchanged. F) A) and C)
G) C) and E)

Question 19

In a head-on collision, an alpha particle  (Z=2) ( Z = 2 ) (Z=2)   of energy  8.20MeV8.20 \mathrm { MeV }8.20MeV  bounces straight back from a nucleus of charge  80.0e80.0 \mathrm { e }80.0e . How close were the centers of the objects at closest approach?  (1eV=1.60( 1 \mathrm { eV } = 1.60(1eV=1.60   ×10−19 J,e=1.60×10−19C,1/4πε0=8.99×109 N⋅m2/C2	imes 10 ^ { - 19 } \mathrm {~J} , e = 1.60 	imes 10 ^ { - 19 } \mathrm { C } , 1 / 4 \pi \varepsilon _ { 0 } = 8.99 	imes 10 ^ { 9 } \mathrm {~N} \cdot \mathrm { m } ^ { 2 } / \mathrm { C } ^ { 2 }×10−19 J,e=1.60×10−19C,1/4πε0​=8.99×109 N⋅m2/C2  )

Accepted Answer

A)    3.39×10−12 m3.39 	imes 10 ^ { - 12 } \mathrm {~m}3.39×10−12 m 
B)    6.56×10−15 m6.56 	imes 10 ^ { - 15 } \mathrm {~m}6.56×10−15 m 
C)    2.81×10−14 m2.81 	imes 10 ^ { - 14 } \mathrm {~m}2.81×10−14 m 
D)    2.17×10−14 m2.17 	imes 10 ^ { - 14 } \mathrm {~m}2.17×10−14 mE) A) and C)
F) B) and C)

Question 20

The nuclei of  24He{ } _ { 2 } ^ { 4 } \mathrm { He }24​He  are also known as

Accepted Answer

A)    α\alphaα  particles.
B)   positrons.
C)    β\betaβ  particles.
D)   x-rays.
E)    γ\gammaγ  rays. F) B) and D)
G) A) and D)

Exam 30: Nuclear Physics and Radioactivity

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$\text { The mean life (time constant) of rubidium-86 is } 26.8 \mathrm {~d} \text {. What is its half-life? }$

Correct Answer
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The main reason that there is a limit to the size of a stable nucleus is

Correct Answer
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The symbol for a certain isotope of strontium is ${ } _ { 38 } ^ { 90 } \mathrm { Sr }$ . What is the mass number of this isotope?

Correct Answer
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If an atomic nucleus containing 64 nucleons has a mass density $\rho$ , what will be the expected mass density of a nucleus containing 512 nucleons?

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
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When a $\beta ^ { - }$ particle is emitted from an unstable nucleus, the atomic mass number of the nucleus

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

Correct Answer
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Isotope A has a decay constant of $0.723 \mathrm {~s} ^ { - 1 }$ and isotope B has a decay constant of $0.514 \mathrm {~s} ^ { - 1 }$ . Which isotope has a longer half-life?

Correct Answer
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$\text { In the radioactive decay equation } { } _ { 92 } ^ { 238 } \rightarrow { } _ { 90 } ^ { 234 } \mathrm { Th } + \mathrm { X } \text {, what is } \mathrm { X } \text { ? }$

Correct Answer
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Correct Answer
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The diameter of an atom is $1.4 \times 10 ^ { - 10 } \mathrm {~m}$ and the diameter of its nucleus is $1.0 \times 10 ^ { - 14 } \mathrm {~m}$ . What fraction of the atom's volume is occupied by its nucleus?

Correct Answer
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When an unstable nucleus decays by emitting an alpha particle, the atomic number $\mathrm { Z }$ of the nucleus

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The nuclei of ${ } _ { 2 } ^ { 4 } \mathrm { He }$ are also known as

Correct Answer
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Rutherfordium-261 has a half-life of $1.08 \mathrm {~min}$ . How long will it take for a sample of rutherfordium to lose one-third of its nuclei?

Correct Answer
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When a $\beta$ - particle is emitted from an unstable nucleus, the atomic number of the nucleus

Correct Answer
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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
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Write the standard nuclear notation for the following nuclei: hydrogen-2, sulfur-33, and lead-207.

Correct Answer
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The decay rate of a radioactive sample decreases from $175 \mathrm { kBq }$ to $12.4 \mathrm { kBq }$ in $18.3 \mathrm {~s}$ . Wha is the half-life of this sample?

Correct Answer
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Exam 30: Nuclear Physics and Radioactivity

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The mean life (time constant) of rubidium-86 is 26.8 d. What is its half-life? \text { The mean life (time constant) of rubidium-86 is } 26.8 \mathrm {~d} \text {. What is its half-life? } The mean life (time constant) of rubidium-86 is 26.8 d. What is its half-life?

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The main reason that there is a limit to the size of a stable nucleus is

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The symbol for a certain isotope of strontium is 3890Sr{ } _ { 38 } ^ { 90 } \mathrm { Sr }3890​Sr . What is the mass number of this isotope?

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If an atomic nucleus containing 64 nucleons has a mass density ρ\rhoρ , what will be the expected mass density of a nucleus containing 512 nucleons?

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When a β−\beta ^ { - }β− particle is emitted from an unstable nucleus, the atomic mass number of the nucleus

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

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Isotope A has a decay constant of 0.723 s−10.723 \mathrm {~s} ^ { - 1 }0.723 s−1 and isotope B has a decay constant of 0.514 s−10.514 \mathrm {~s} ^ { - 1 }0.514 s−1 . Which isotope has a longer half-life?

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Correct AnswerverifiedShow Answer

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The diameter of an atom is 1.4×10−10 m1.4 \times 10 ^ { - 10 } \mathrm {~m}1.4×10−10 m and the diameter of its nucleus is 1.0×10−14 m1.0 \times 10 ^ { - 14 } \mathrm {~m}1.0×10−14 m . What fraction of the atom's volume is occupied by its nucleus?

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When an unstable nucleus decays by emitting an alpha particle, the atomic number Z\mathrm { Z }Z of the nucleus

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The nuclei of 24He{ } _ { 2 } ^ { 4 } \mathrm { He }24​He are also known as

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Rutherfordium-261 has a half-life of 1.08 min1.08 \mathrm {~min}1.08 min . How long will it take for a sample of rutherfordium to lose one-third of its nuclei?

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

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Write the standard nuclear notation for the following nuclei: hydrogen-2, sulfur-33, and lead-207.

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The decay rate of a radioactive sample decreases from 175kBq175 \mathrm { kBq }175kBq to 12.4kBq12.4 \mathrm { kBq }12.4kBq in 18.3 s18.3 \mathrm {~s}18.3 s . Wha is the half-life of this sample?

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Correct Answer
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Correct Answer
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$\text { The mean life (time constant) of rubidium-86 is } 26.8 \mathrm {~d} \text {. What is its half-life? }$

Correct Answer
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Correct Answer
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The symbol for a certain isotope of strontium is ${ } _ { 38 } ^ { 90 } \mathrm { Sr }$ . What is the mass number of this isotope?

Correct Answer
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If an atomic nucleus containing 64 nucleons has a mass density $\rho$ , what will be the expected mass density of a nucleus containing 512 nucleons?

Correct Answer
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Correct Answer
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When a $\beta ^ { - }$ particle is emitted from an unstable nucleus, the atomic mass number of the nucleus

Correct Answer
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Correct Answer
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Isotope A has a decay constant of $0.723 \mathrm {~s} ^ { - 1 }$ and isotope B has a decay constant of $0.514 \mathrm {~s} ^ { - 1 }$ . Which isotope has a longer half-life?

Correct Answer
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Correct Answer
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Correct Answer
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The diameter of an atom is $1.4 \times 10 ^ { - 10 } \mathrm {~m}$ and the diameter of its nucleus is $1.0 \times 10 ^ { - 14 } \mathrm {~m}$ . What fraction of the atom's volume is occupied by its nucleus?

Correct Answer
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When an unstable nucleus decays by emitting an alpha particle, the atomic number $\mathrm { Z }$ of the nucleus

Correct Answer
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The nuclei of ${ } _ { 2 } ^ { 4 } \mathrm { He }$ are also known as

Correct Answer
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Rutherfordium-261 has a half-life of $1.08 \mathrm {~min}$ . How long will it take for a sample of rutherfordium to lose one-third of its nuclei?

Correct Answer
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When a $\beta$ - particle is emitted from an unstable nucleus, the atomic number of the nucleus

Correct Answer
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Correct Answer
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Correct Answer
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The decay rate of a radioactive sample decreases from $175 \mathrm { kBq }$ to $12.4 \mathrm { kBq }$ in $18.3 \mathrm {~s}$ . Wha is the half-life of this sample?

Correct Answer
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