Question 1

The reaction   is known as a ____ reaction.

Accepted Answer

A)  beta capture 
B)  beta emission 
C)  neutron capture 
D)  neutron emission 
E)  photon emission 
A)  beta capture 
B)  beta emission 
C)  neutron capture 
D)  neutron emission 
E)  photon emission

Question 2

When a beam of nuclear radiation of initial intensity I0 passes through a thickness x of material, the intensity of the beam exiting the material is I =

Accepted Answer

A)  I0e−μx. 
B)  I0eμx. 
C)  I0(e−μx − 1). 
D)  I0(eμx − 1). 
E)  I0(1 − e−μx). 
A)  I0e−μx. 
B)  I0eμx. 
C)  I0(e−μx − 1). 
D)  I0(eμx − 1). 
E)  I0(1 − e−μx).

Question 3

The nuclear probability of interacting with neutrons depends most strongly on the neutron's

Accepted Answer

A)  mass 
B)  area 
C)  volume 
D)  speed 
E)  charge 
A)  mass 
B)  area 
C)  volume 
D)  speed 
E)  charge

Question 4

A neutron is characterized by the term "thermal neutron" when

Accepted Answer

A)  its energy is of the order kT, where T is on the order of 0°C. 
B)  its energy is of the order kT, where T is on the order of 0 K. 
C)  its energy is of the order kT, where T is on the order of 273°C. 
D)  its energy is of the order kT, where T is on the order of 100°C. 
E)  its energy is of the order kT, where T is on the order of 0°R. 
A)  its energy is of the order kT, where T is on the order of 0°C. 
B)  its energy is of the order kT, where T is on the order of 0 K. 
C)  its energy is of the order kT, where T is on the order of 273°C. 
D)  its energy is of the order kT, where T is on the order of 100°C. 
E)  its energy is of the order kT, where T is on the order of 0°R.

Question 5

44 g of petrified wood was found in a petrified forest. A sample showed a 14C activity of 100 decays/minute. How long has the tree been dead (in years)? (The half-life of carbon-14 is 5730 years and freshly cut wood contains 6.5 × 1010 atoms of 14C per gram.)

Accepted Answer

A)  12300 
B)  15600 
C)  8500 
D)  4700 
E)  2400 
A)  12300 
B)  15600 
C)  8500 
D)  4700 
E)  2400

Question 6

A glass container holds equal numbers of atoms of phosphorus 30 with a half-life of 2.5 minutes and of nitrogen 13 with a half-life of 10 minutes. After 20 minutes the ratio of the number of nitrogen atoms remaining to the number of phosphorus atoms remaining is

Accepted Answer

A) 
  . 
B) 
  . 
C) 
  . 
D)  64. 
E)  256. 
A) 
  . 
B) 
  . 
C) 
  . 
D)  64. 
E)  256.

Question 7

Background radiation from cosmic rays and radioactive nuclei in our surroundings is about 0.13 rem/year. Suppose we assume this all comes from cosmic rays which have an RBE factor of 1.0. The RBE factor for the most dangerous types of radiation is 20. How many rads of the most dangerous radiation could a 100-year-old person have been exposed to in her lifetime without having gone over the recommended limit of 0.5 rem/year?

Accepted Answer

A)  0.37 
B)  0.50 
C)  1.85 
D)  13 
E)  37 
A)  0.37 
B)  0.50 
C)  1.85 
D)  13 
E)  37

Question 8

Two nuclei which share the same atomic number Z always are

Accepted Answer

A)  stable. 
B)  unstable. 
C)  isotopes. 
D)  isobars. 
E)  radioactive. 
A)  stable. 
B)  unstable. 
C)  isotopes. 
D)  isobars. 
E)  radioactive.

Question 9

One roentgen is defined as

Accepted Answer

A)  the amount of ionizing radiation that will produce 1/3 × 10−9 C of electric charge in 1 cm3 of air under standard conditions. 
B)  the amount of radiation that deposits 10−2 J of energy into 1 kg of absorbing material. 
C)  the amount of radiation needed for ionization of an atom. 
D)  the amount of radiation needed for dissociation of a molecule. 
E)  the amount of radiation that deposits 1 erg of energy in 1 g of air. 
A)  the amount of ionizing radiation that will produce 1/3 × 10−9 C of electric charge in 1 cm3 of air under standard conditions. 
B)  the amount of radiation that deposits 10−2 J of energy into 1 kg of absorbing material. 
C)  the amount of radiation needed for ionization of an atom. 
D)  the amount of radiation needed for dissociation of a molecule. 
E)  the amount of radiation that deposits 1 erg of energy in 1 g of air.

Question 10

A principal mechanism for energy loss during nuclear fusion is bremsstrahlung. This loss is associated with

Accepted Answer

A)  x-rays emitted due to electron-ion collisions. 
B)  radiation losses due to T4 losses. 
C)  conduction losses associated with ΔT. 
D)  convection losses associated with ΔT. 
E)  neutron collisions with atoms of moderator. 
A)  x-rays emitted due to electron-ion collisions. 
B)  radiation losses due to T4 losses. 
C)  conduction losses associated with ΔT. 
D)  convection losses associated with ΔT. 
E)  neutron collisions with atoms of moderator.

Question 11

How much energy (in MeV) is released when a   fissions to   and   in the reaction   m(n) = 1.008665 u m(U) = 235.043915 u
M(Ba) = 140.9139 u
M(Kr) = 91.8973 u
U = 1.66 × 10−27 kg

Accepted Answer

A)  100 
B)  50 
C)  200 
D)  150 
E)  250 
A)  100 
B)  50 
C)  200 
D)  150 
E)  250

Question 12

The nuclear reaction(s) that is(are) most likely to be employed in fusion reactors on Earth is(are)

Accepted Answer

A) 
  . 
B) 
  . 
C) 
  . 
D)  all of the above. 
E)  only (a) and (b) above. 
A) 
  . 
B) 
  . 
C) 
  . 
D)  all of the above. 
E)  only (a) and (b) above.

Question 13

A neutron is known to undergo beta decay (n → p + e− +   ). A reasonable mean lifetime for free neutrons is

Accepted Answer

A)  10 years 
B)  10 hours 
C)  10 days 
D)  10 minutes 
E)  10−23 s 
A)  10 years 
B)  10 hours 
C)  10 days 
D)  10 minutes 
E)  10−23 s

Question 14

When a fast neutron collides with a hydrogen or deuterium nucleus, the most likely result is that

Accepted Answer

A)  the neutron has an appreciable gain in kinetic energy, the gain being greatest for head-on collisions. 
B)  the neutron has an appreciable gain in kinetic energy, the gain being greatest for oblique collisions. 
C)  the neutron has an appreciable loss in kinetic energy, the loss being greatest for head-on collisions. 
D)  the neutron has an appreciable loss in kinetic energy, the loss being greatest for oblique collisions. 
E)  the neutron is absorbed by the hydrogen or deuterium nucleus. 
A)  the neutron has an appreciable gain in kinetic energy, the gain being greatest for head-on collisions. 
B)  the neutron has an appreciable gain in kinetic energy, the gain being greatest for oblique collisions. 
C)  the neutron has an appreciable loss in kinetic energy, the loss being greatest for head-on collisions. 
D)  the neutron has an appreciable loss in kinetic energy, the loss being greatest for oblique collisions. 
E)  the neutron is absorbed by the hydrogen or deuterium nucleus.

Question 15

Calculate the binding energy per nucleon (MeV/nucleon) for tritium, (   ) a radioactive isotope of hydrogen. Assume:
M p = 1.007 825 u
M n = 1.008 665 u
M t = 3.016 05 u
U = 1.66 × 10−27 kg

Accepted Answer

A)  2.8 
B)  3.1 
C)  1.0 
D)  8.5 
E)  2.1 
A)  2.8 
B)  3.1 
C)  1.0 
D)  8.5 
E)  2.1

Question 16

How many radioactive atoms are present in a sample that has an activity of 0.5 μCi and a half-life of 10 years? (1 curie = 3.7 × 1010 decays/s)

Accepted Answer

A)  9.5 × 1012 atoms 
B)  8.4 × 1012 atoms 
C)  7.3 × 1012 atoms 
D)  6.5 × 1012 atoms 
E)  2.7 × 105 atoms 
A)  9.5 × 1012 atoms 
B)  8.4 × 1012 atoms 
C)  7.3 × 1012 atoms 
D)  6.5 × 1012 atoms 
E)  2.7 × 105 atoms

Question 17

When a neutron decays, a proton and an electron are observed. When the electrons emitted from a sample of neutrons are observed, they are found to have different kinetic energies. This was accounted for by

Accepted Answer

A)  introducing a different particle, the neutrino. 
B)  introducing the effect of gravity on the particles. 
C)  including the kinetic energies of the neutron and proton. 
D)  modifying the laws of conservation of momentum and energy. 
E)  taking into account the uncertainties associated with Heisenberg's Uncertainty Principle. 
A)  introducing a different particle, the neutrino. 
B)  introducing the effect of gravity on the particles. 
C)  including the kinetic energies of the neutron and proton. 
D)  modifying the laws of conservation of momentum and energy. 
E)  taking into account the uncertainties associated with Heisenberg's Uncertainty Principle.

Question 18

It is often possible to use atomic masses when calculating the binding energy of a nucleus. This is not true for calculating the Q value for the e+ decay process since

Accepted Answer

A)  the electron masses do not cancel. 
B)  a positron is an antiparticle. 
C)  the electron masses cancel. 
D)  the mass of a positron cannot be neglected when compared to the mass of a nucleus. 
E)  none of the above. 
A)  the electron masses do not cancel. 
B)  a positron is an antiparticle. 
C)  the electron masses cancel. 
D)  the mass of a positron cannot be neglected when compared to the mass of a nucleus. 
E)  none of the above.

Question 19

The theory of nuclear astrophysics is that all the heavy elements like uranium are formed in the interior of massive stars. These stars eventually explode, releasing these elements into space. If we assume that at the time of the explosion there were equal amount of U-235 and U-238, how long ago did the star(s) explode that released the elements that formed our Earth? The present U-235/U-238 ratio is 0.0070. [The half-lives of U-235 and U-238 are 0.7 × 109 yr and 4.47 × 109 yr.]

Accepted Answer

Question 20

What value of Z (atomic number) and A (mass number) result in the following alpha decay?

Accepted Answer

A)  Z = 92; A = 238 
B)  Z = 91; A = 238 
C)  Z = 90; A = 234 
D)  Z = 93; A = 238 
E)  Z = 88; A = 236 
A)  Z = 92; A = 238 
B)  Z = 91; A = 238 
C)  Z = 90; A = 234 
D)  Z = 93; A = 238 
E)  Z = 88; A = 236

Exam 44: Nuclear Structure

The reaction is known as a ____ reaction.

When a beam of nuclear radiation of initial intensity I0 passes through a thickness x of material, the intensity of the beam exiting the material is I =

The nuclear probability of interacting with neutrons depends most strongly on the neutron's

A neutron is characterized by the term "thermal neutron" when

44 g of petrified wood was found in a petrified forest. A sample showed a 14C activity of 100 decays/minute. How long has the tree been dead (in years)? (The half-life of carbon-14 is 5730 years and freshly cut wood contains 6.5 × 1010 atoms of 14C per gram.)

A glass container holds equal numbers of atoms of phosphorus 30 with a half-life of 2.5 minutes and of nitrogen 13 with a half-life of 10 minutes. After 20 minutes the ratio of the number of nitrogen atoms remaining to the number of phosphorus atoms remaining is

Two nuclei which share the same atomic number Z always are

One roentgen is defined as

A principal mechanism for energy loss during nuclear fusion is bremsstrahlung. This loss is associated with

How much energy (in MeV) is released when a fissions to and in the reaction m(n) = 1.008665 u m(U) = 235.043915 u M(Ba) = 140.9139 u M(Kr) = 91.8973 u U = 1.66 × 10−27 kg

The nuclear reaction(s) that is(are) most likely to be employed in fusion reactors on Earth is(are)

A neutron is known to undergo beta decay (n → p + e− + ). A reasonable mean lifetime for free neutrons is

When a fast neutron collides with a hydrogen or deuterium nucleus, the most likely result is that

Calculate the binding energy per nucleon (MeV/nucleon) for tritium, ( ) a radioactive isotope of hydrogen. Assume: M p = 1.007 825 u M n = 1.008 665 u M t = 3.016 05 u U = 1.66 × 10−27 kg

How many radioactive atoms are present in a sample that has an activity of 0.5 μCi and a half-life of 10 years? (1 curie = 3.7 × 1010 decays/s)

When a neutron decays, a proton and an electron are observed. When the electrons emitted from a sample of neutrons are observed, they are found to have different kinetic energies. This was accounted for by

It is often possible to use atomic masses when calculating the binding energy of a nucleus. This is not true for calculating the Q value for the e+ decay process since

What value of Z (atomic number) and A (mass number) result in the following alpha decay?

Physics and Measurement

Motion in One Dimension

Vectors

Motion in Two Dimensions

The Laws of Motion

Circular Motion and Other Applications of Newtons Laws

Energy of a System

Conservation of Energy

Linear Momentum and Collisions

Rotation of a Rigid Object About a Fixed Axis

Angular Momentum

Static Equilibrium and Elasticity

Universal Gravitation

Fluid Mechanics

Oscillatory Motion

Wave Motion

Superposition and Standing Waves

Temperature

The First Law of Thermodynamics

The Kinetic Theory of Gases

Heat Engines, Entropy, and the Second Law of Thermodynamics

Electric Fields

Gausss Law

Electric Potential

Capacitance and Dielectrics

Current and Resistance

Direct-Current Circuits

Magnetic Fields

Sources of the Magnetic Field

Faradays Law

Inductance

Alternating-Current Circuits

Electromagnetic Waves

The Nature of Light and the Principles of Ray Optics

Image Formation

Wave Optics

Diffraction Patterns and Polarization

Relativity

Introduction to Quantum Physics

Quantum Mechanics

Atomic Physics

Molecules and Solids

Particle Physics and Cosmology

Filters

When a beam of nuclear radiation of initial intensity I₀ passes through a thickness x of material, the intensity of the beam exiting the material is I =

44 g of petrified wood was found in a petrified forest. A sample showed a ¹⁴C activity of 100 decays/minute. How long has the tree been dead (in years)? (The half-life of carbon-14 is 5730 years and freshly cut wood contains 6.5 × 10¹⁰ atoms of ¹⁴C per gram.)

How much energy (in MeV) is released when a fissions to and in the reaction m(n) = 1.008665 u m(U) = 235.043915 u M(Ba) = 140.9139 u M(Kr) = 91.8973 u U = 1.66 × 10−²⁷ kg

Calculate the binding energy per nucleon (MeV/nucleon) for tritium, ( ) a radioactive isotope of hydrogen. Assume: M _p = 1.007 825 u M _n = 1.008 665 u M _t = 3.016 05 u U = 1.66 × 10−²⁷ kg

How many radioactive atoms are present in a sample that has an activity of 0.5 μCi and a half-life of 10 years? (1 curie = 3.7 × 10¹⁰ decays/s)

It is often possible to use atomic masses when calculating the binding energy of a nucleus. This is not true for calculating the Q value for the e⁺ decay process since