Question 1

A beta particle is:

Accepted Answer

A)   a helium nucleus
B)   an electron or a positron
C)   a radioactive element
D)   any negative particle
E)   a hydrogen atomF) B) and C)
G) A) and D)

Question 2

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)   2" class="answers-bank-image d-inline" rel="preload" >
E)   Z = A2F) A) and B)
G) C) and D)

Question 3

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) B) and C)
G) A) and C)

Question 4

The mass density of an atomic nucleus is:

Accepted Answer

A)   about 1015 kg/m3
B)   about 1012 kg/m3
C)   increases with increasing nuclear mass
D)   increases with decreasing nuclear radius
E)   about the same as that of all other nucleiF) A) and C)
G) B) and C)

Question 5

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) C) and D)
G) All of the above

Question 6

Volumes of atomic nuclei are proportional to:

Accepted Answer

A)   the mass number
B)   the atomic number
C)   the total nuclear spin
D)   the number of neutrons
E)   none of theseF) B) and E)
G) None of the above

Question 7

In an alpha decay the disintegration energy appears as:

Accepted Answer

A)   photon energies
B)   the kinetic energies of the alpha and the daughter nucleus
C)   the excitation energy of the daughter nucleus
D)   the excitation energy of the alpha particle
E)   heatF) A) and D)
G) B) and C)

Question 8

Let Z denote the atomic number and A denote the mass number of a nucleus. The number of neutrons in this nucleus is:

Accepted Answer

A)   Z
B)   A - Z
C)   A - 2Z
D)   A
E)   2A - ZF) C) and D)
G) None of the above

Question 9

The 66Cu (Z = 29)  produced in a nuclear bombardment is unstable, changing to 66Zn (Z = 30)  by the emission of:

Accepted Answer

A)   a proton
B)   a gamma ray photon
C)   a positron
D)   an electron
E)   an alpha particleF) C) and D)
G) A) and B)

Question 10

Of the following which has the smallest rest energy?

Accepted Answer

A)   A neutron
B)   An electron
C)   An ion
D)   A proton
E)   An atomF) B) and D)
G) B) and C)

Question 11

Starting with a sample of pure 66Cu, 7/8 of it decays into Zn in 15 minutes. The corresponding half-life is:

Accepted Answer

A)   15 minutes
B)   5 minutes
C)   7 minutes
D)   3.75 minutes
E)   10 minutesF) C) and D)
G) A) and E)

Question 12

The energies of electrons emitted in  β\betaβ - decays have a continuous spectrum because:

Accepted Answer

A)   the original neutron has a continuous spectrum
B)   the neutrino can carry off energy
C)   the emitted electron is free
D)   energy is not conserved
E)   the daughter nucleus may have any energy F) None of the above
G) All of the above

Question 13

Iron has atomic number 26. Naturally mined iron contains isotopes of mass numbers 54, 56, 57, and 58. Which of the following statements is FALSE?

Accepted Answer

A)   every atom of iron has 26 protons
B)   some iron atoms have 30 neutrons
C)   some iron atoms have 54 neutrons
D)   the isotopes may be separated in a mass spectrometer
E)   there are four kinds of naturally occurring iron atoms with the same chemical propertiesF) All of the above
G) C) and D)

Question 14

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) A) and D)
G) A) and E)

Question 15

A radioactive atom X emits a  β\betaβ - particle. The resulting atom:

Accepted Answer

A)   must be very reactive chemically
B)   has an atomic number that is one more than that of X
C)   has a mass number that is one less than that of X
D)   must be radioactive
E)   is the same chemical element as X F) B) and C)
G) A) and B)

Question 16

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) None of the above
G) D) and E)

Question 17

The relation between the disintegration constant  λ\lambdaλ and the half-life T of a radioactive substance is:

Accepted Answer

A)    λ\lambdaλ  = 2T
B)    λ\lambdaλ  = 1/T
C)    λ\lambdaλ  = 2/T
D)    λ\lambdaλ T = ln 2
E)    λ\lambdaλ T = ln(1/2)  F) A) and B)
G) C) and E)

Question 18

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) All of the above
G) A) and C)

Question 19

The becquerel 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) All of the above
G) None of the above

Question 20

Rank the following collections of particles according to the total binding energy of all the particles in each collection, least to greatest.

Accepted Answer

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

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?

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The 66Cu (Z = 29) produced in a nuclear bombardment is unstable, changing to 66Zn (Z = 30) by the emission of:

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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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The energies of electrons emitted in β\betaβ - decays have a continuous spectrum because:

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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 ______ β\betaβ - particles:

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The mass density of an atomic nucleus is:

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Rank the following collections of particles according to the total binding energy of all the particles in each collection, least to greatest.

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

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In an alpha decay the disintegration energy appears as:

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Volumes of atomic nuclei are proportional to:

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

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Of the following which has the smallest rest energy?

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A beta particle is:

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

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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:

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Let Z denote the atomic number and A denote the mass number of a nucleus. The number of neutrons in this nucleus is:

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Starting with a sample of pure 66Cu, 7/8 of it decays into Zn in 15 minutes. The corresponding half-life is:

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Iron has atomic number 26. Naturally mined iron contains isotopes of mass numbers 54, 56, 57, and 58. Which of the following statements is FALSE?

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A radioactive atom X emits a β\betaβ - particle. The resulting atom:

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The relation between the disintegration constant λ\lambdaλ and the half-life T of a radioactive substance is:

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The ⁶⁶Cu (Z = 29) produced in a nuclear bombardment is unstable, changing to ⁶⁶Zn (Z = 30) by the emission of:

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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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The energies of electrons emitted in $\beta$ ^- decays have a continuous spectrum because:

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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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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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Starting with a sample of pure ⁶⁶Cu, 7/8 of it decays into Zn in 15 minutes. The corresponding half-life is:

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A radioactive atom X emits a $\beta$ ^- particle. The resulting atom:

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The relation between the disintegration constant $\lambda$ and the half-life T of a radioactive substance is:

Correct Answer
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