Question 1

Let A be the mass number and Z be the atomic number of a nucleus.Which of the following is approximately correct for light nuclei?

Accepted Answer

A)  Z = 2A
B)  Z = A
C)  Z = A/2
D)  Z =
E)  Z = A2F) All of the above
G) B) and E)

Question 2

The half-life of a given nuclear disintegration A  →\rightarrow→  B:

Accepted Answer

A)  depends on the initial number of A atoms
B)  depends on the initial number of B atoms
C)  is an exponentially increasing function of time
D)  is an exponentially decreasing function of time
E)  none of the above F) C) and D)
G) A) and C) E

Question 3

In addition to the daughter nucleus and an electron or positron, the products of a beta decay include:

Accepted Answer

A)  a neutron
B)  a neutrino
C)  a proton
D)  an alpha particle
E)  no other particleF) A) and D)
G) All of the above

Question 4

A nucleus with mass number A and atomic number Z undergoes  β\betaβ + decay.The mass number and atomic number, respectively, of the daughter nucleus are:

Accepted Answer

A)  A - 1, Z - 1
B)  A - 1, Z + 1
C)  A + 1, Z - 1
D)  A, Z + 1
E)  A, Z - 1 F) B) and D)
G) None of the above

Question 5

The sievert is the correct unit to use in reporting the measurement of:

Accepted Answer

A)  the rate of decay of a radioactive source
B)  the ability of a beam of gamma ray photons to produce ions in a target
C)  the energy delivered by radiation to a target
D)  the biological effect of radiation
E)  none of the aboveF) A) and E)
G) A) and D)

Question 6

The half-life of a radioactive isotope is 6.5 h.If there are initially 48 *1032 atoms of this isotope, the number of atoms of this isotope remaining after 26 h is:

Accepted Answer

A)  12 * 1032
B)  6 * 1032
C)  3 * 1032
D)  6 * 104
E)  3 * 102F) B) and D)
G) All of the above

Question 7

Magnesium has atomic number 12, hydrogen has atomic number 1, and helium has atomic number 2.In the nuclear reaction 24Mg + 2H  →\rightarrow→  ( ) + 4He the missing quantity is:

Accepted Answer

A)  "23Na (Z = 11) "
B)  "22Ne (Z = 10) "
C)  "21Na (Z = 11) "
D)  "21Ne (Z = 10) "
E)  "22Na (Z = 11) " F) C) and D)
G) B) and C)

Question 8

Stable nuclei generally:

Accepted Answer

A)  have a greater number of protons than neutrons
B)  have low mass numbers
C)  have high mass numbers
D)  are beta emitters
E)  none of the aboveF) A) and B)
G) B) and E)

Question 9

A large collection of nuclei are undergoing alpha decay.The rate of decay at any instant is proportional to:

Accepted Answer

A)  the number of undecayed nuclei present at that instant
B)  the time since the decays started
C)  the time remaining before all have decayed
D)  the half-life of the decay
E)  the average time between decaysF) C) and D)
G) B) and E)

Question 10

The mass density of an atomic nucleus:

Accepted Answer

A)  is about 1015 kg/m3
B)  is about 1012 kg/m3
C)  increases with increasing nuclear mass
D)  increases with decreasing nuclear radius
E)  is roughly constant independent of atomic numberF) D) and E)
G) C) and D)

Question 11

A nucleus with mass number A and atomic number Z emits an alpha particle.The mass number and atomic number, respectively, of the daughter nucleus are:

Accepted Answer

A)  A, Z -2
B)  A - 2, Z - 2
C)  A - 2, Z
D)  A - 4, Z
E)  A - 4, Z - 2F) B) and D)
G) None of the above

Question 12

A nucleus with mass number A and atomic number Z undergoes  β\betaβ - decay.The mass number and atomic number, respectively, of the daughter nucleus are:

Accepted Answer

A)  A, Z - 1.0
B)  A - 1, Z
C)  A + 1, Z - 1
D)  A, Z + 1
E)  A, Z - 1 F) C) and E)
G) A) and B)

Question 13

If a nucleus has mass M, Z protons (mass mp) and N neutrons (mass mn) its binding energy is equal to:

Accepted Answer

A)  Mc2
B)  (M - Zmp - Nmn) c2
C)  (Zmp + Nmn - M) c2
D)  (Zmp + Nmn) c2
E)  (Zmp - M) c2F) A) and D)
G) A) and E)

Question 14

Some alpha emitters have longer half-lives than others because:

Accepted Answer

A)  their alpha particles have greater mass
B)  their alpha particles have less mass
C)  their barriers to decay are higher and wider
D)  their barriers to decay are lower and narrower
E)  their decays include the emission of a photonF) D) and E)
G) A) and E)

Question 15

An atom of 235U (Z = 92) disintegrates to 207Pb (Z = 82) with a half-life of about a billion years by emitting seven alpha particles and ______  β\betaβ - particles:

Accepted Answer

A)  3
B)  4
C)  5
D)  6
E)  7 F) A) and B)
G) A) and C)

Question 16

A radium atom, 226Ra (Z = 86) , emits an alpha particle.The number of protons in the resulting atom is:

Accepted Answer

A)  84
B)  85
C)  86
D)  88
E)  some other numberF) C) and E)
G) A) and E)

Question 17

The graph shows the decay rate R as a function of the time t for three radioactive samples.Rank the samples according to their half-lives, shortest to longest.

Accepted Answer

A)  1, 2 ,3
B)  1, 3, 2
C)  2, 1, 3
D)  2, 3, 1
E)  3, 1, 2F) C) and E)
G) A) and C) C

Question 18

The greatest binding energy per nucleon occurs for nuclides with masses near that of:

Accepted Answer

A)  helium
B)  sodium
C)  iron
D)  mercury
E)  uraniumF) All of the above
G) B) and E)

Question 19

The relationship between the activity R, the disintegration constant λ, and the remaining number N of radioactive nuclei is:

Accepted Answer

A)  N = λR
B)  R = λN
C)  R = λ/N
D)  R = N/ λ
E)  R = λ ln NF) B) and D)
G) A) and D)

Question 20

The model of the nucleus in which each nucleon has its own well-defined quantum numbers is called the:

Accepted Answer

A)  collective model
B)  quantum model
C)  liquid drop model
D)  independent model
E)  atomic modelF) C) and D)
G) A) and E) D

Exam 42: Nuclear Physics

Let A be the mass number and Z be the atomic number of a nucleus.Which of the following is approximately correct for light nuclei?

Correct AnswerverifiedShow Answer

The half-life of a given nuclear disintegration A →\rightarrow→ B:

Correct AnswerverifiedE

In addition to the daughter nucleus and an electron or positron, the products of a beta decay include:

Correct AnswerverifiedShow Answer

A nucleus with mass number A and atomic number Z undergoes β\betaβ + decay.The mass number and atomic number, respectively, of the daughter nucleus are:

Correct AnswerverifiedShow Answer

The sievert is the correct unit to use in reporting the measurement of:

Correct AnswerverifiedShow Answer

The half-life of a radioactive isotope is 6.5 h.If there are initially 48 *1032 atoms of this isotope, the number of atoms of this isotope remaining after 26 h is:

Correct AnswerverifiedShow Answer

Magnesium has atomic number 12, hydrogen has atomic number 1, and helium has atomic number 2.In the nuclear reaction 24Mg + 2H →\rightarrow→ ( ) + 4He the missing quantity is:

Correct AnswerverifiedShow Answer

Stable nuclei generally:

Correct AnswerverifiedShow Answer

A large collection of nuclei are undergoing alpha decay.The rate of decay at any instant is proportional to:

Correct AnswerverifiedShow Answer

The mass density of an atomic nucleus:

Correct AnswerverifiedShow Answer

A nucleus with mass number A and atomic number Z emits an alpha particle.The mass number and atomic number, respectively, of the daughter nucleus are:

Correct AnswerverifiedShow Answer

A nucleus with mass number A and atomic number Z undergoes β\betaβ - decay.The mass number and atomic number, respectively, of the daughter nucleus are:

Correct AnswerverifiedShow Answer

If a nucleus has mass M, Z protons (mass mp) and N neutrons (mass mn) its binding energy is equal to:

Correct AnswerverifiedShow Answer

Some alpha emitters have longer half-lives than others because:

Correct AnswerverifiedShow Answer

An atom of 235U (Z = 92) disintegrates to 207Pb (Z = 82) with a half-life of about a billion years by emitting seven alpha particles and ______ β\betaβ - particles:

Correct AnswerverifiedShow Answer

A radium atom, 226Ra (Z = 86) , emits an alpha particle.The number of protons in the resulting atom is:

Correct AnswerverifiedShow Answer

The graph shows the decay rate R as a function of the time t for three radioactive samples.Rank the samples according to their half-lives, shortest to longest.

Correct AnswerverifiedC

The greatest binding energy per nucleon occurs for nuclides with masses near that of:

Correct AnswerverifiedShow Answer

The relationship between the activity R, the disintegration constant λ, and the remaining number N of radioactive nuclei is:

Correct AnswerverifiedShow Answer

The model of the nucleus in which each nucleon has its own well-defined quantum numbers is called the:

Correct AnswerverifiedD

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The half-life of a given nuclear disintegration A $\rightarrow$ B:

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E

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A nucleus with mass number A and atomic number Z undergoes $\beta$ ⁺ decay.The mass number and atomic number, respectively, of the daughter nucleus are:

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The half-life of a radioactive isotope is 6.5 h.If there are initially 48 *10³² atoms of this isotope, the number of atoms of this isotope remaining after 26 h is:

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Magnesium has atomic number 12, hydrogen has atomic number 1, and helium has atomic number 2.In the nuclear reaction ²⁴Mg + ²H $\rightarrow$ ( ) + ⁴He the missing quantity is:

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A nucleus with mass number A and atomic number Z undergoes $\beta$ ^- decay.The mass number and atomic number, respectively, of the daughter nucleus are:

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If a nucleus has mass M, Z protons (mass m_p) and N neutrons (mass m_n) its binding energy is equal to:

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An atom of ²³⁵U (Z = 92) disintegrates to ²⁰⁷Pb (Z = 82) with a half-life of about a billion years by emitting seven alpha particles and ______ $\beta$ ^- particles:

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A radium atom, ²²⁶Ra (Z = 86) , emits an alpha particle.The number of protons in the resulting atom is:

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C

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D