Question 1

The word isotopes describes elements that have

Accepted Answer

A) the same atomic number but different atomic mass. 
B) the same atomic mass but different atomic number. 
C) the same atomic mass and the same atomic number but different chemical properties. 
D) similar chemical properties,though they differ in both atomic mass and atomic number. 
E) the same number of valence electrons. 
A) the same atomic number but different atomic mass. 
B) the same atomic mass but different atomic number. 
C) the same atomic mass and the same atomic number but different chemical properties. 
D) similar chemical properties,though they differ in both atomic mass and atomic number. 
E) the same number of valence electrons.

Question 2

In what type of radioactive decay are the mass numbers of the parent and daughter nuclei the same?

Accepted Answer

A) alpha 
B) beta 
C) gamma 
D) both alpha and beta 
E) both beta and gamma 
A) alpha 
B) beta 
C) gamma 
D) both alpha and beta 
E) both beta and gamma

Question 3

About 200 MeV of energy is released in the average fission reaction.Most of this energy is

Accepted Answer

A) kinetic energy of fission neutrons. 
B) kinetic energy of fission fragments. 
C) energy of $\beta$- and $\gamma$ rays. 
D) energy of a particles and $\gamma$ rays. 
E) electromagnetic radiation in the visible portion of the spectrum. 
A) kinetic energy of fission neutrons. 
B) kinetic energy of fission fragments. 
C) energy of $\beta$- and $\gamma$ rays. 
D) energy of a particles and $\gamma$ rays. 
E) electromagnetic radiation in the visible portion of the spectrum.

Question 4

The nuclear radius of   is approximately

Accepted Answer

A) 1.05 fm 
B) 4.50 fm 
C) 0.350 fm 
D) 11.2 fm 
E) 1.85 fm 
A) 1.05 fm 
B) 4.50 fm 
C) 0.350 fm 
D) 11.2 fm 
E) 1.85 fm

Question 5

The fact that most $\alpha$ emitters show a group of discrete $\alpha$-particle energies,rather than a single energy,can best be explained by which of the following?

Accepted Answer

A) $\alpha$ particles and $\beta$ particles are emitted from the same unstable nucleus,and because the $\beta$ particles exhibit discrete energies,so must the $\alpha$ particles. 
B) The parent can decay by $\alpha$ emission to any one of a number of allowed energy states of the daughter. 
C) An $\alpha$-emitting parent normally decays to many different daughter elements. 
D) $\alpha$ emission is accompanied by neutrino emission. 
E) Varying amounts of energy are required to tunnel through the nuclear potential well. 
A) $\alpha$ particles and $\beta$ particles are emitted from the same unstable nucleus,and because the $\beta$ particles exhibit discrete energies,so must the $\alpha$ particles. 
B) The parent can decay by $\alpha$ emission to any one of a number of allowed energy states of the daughter. 
C) An $\alpha$-emitting parent normally decays to many different daughter elements. 
D) $\alpha$ emission is accompanied by neutrino emission. 
E) Varying amounts of energy are required to tunnel through the nuclear potential well.

Question 6

The unifying concepts in physics are the conservation laws.To preserve these laws in nuclear processes,it became necessary to postulate the existence of

Accepted Answer

A) the positron. 
B) particle spin. 
C) space quantization. 
D) the neutrino. 
E) the neutron. 
A) the positron. 
B) particle spin. 
C) space quantization. 
D) the neutrino. 
E) the neutron.

Question 7

A radioactive source has a half-life of 2 min.At time t = 0 it is placed near a detector and the counting rate is observed to be 3000 counts/s.If the detection efficiency is 25%,how many radioactive nuclei are there at time t = 0?

Accepted Answer

A) 1.04 $\times$ 106  
B) 1.67 $\times$ 106  
C) 2.08 $\times$ 106  
D) 3.41 $\times$ 106  
E) 3.79 $\times$ 106  
A) 1.04 $\times$ 106  
B) 1.67 $\times$ 106  
C) 2.08 $\times$ 106  
D) 3.41 $\times$ 106  
E) 3.79 $\times$ 106

Question 8

A sphere of radius r1 collides with a sphere of radius r2.The cross section for a contact collision is

Accepted Answer

A) $\pi$r 
B) 2$\pi$r2  
C) ½$\pi$(r1 + r2)2  
D) $\pi$(r1 + r2)2  
A) $\pi$r 
B) 2$\pi$r2  
C) ½$\pi$(r1 + r2)2  
D) $\pi$(r1 + r2)2

Question 9

An old piece of dead wood contains 38% of the 14C abundance of a living sample.How old is it? (The half-life of 14C is 5730 years.)

Accepted Answer

A) 3.95 $\times$ 103 years 
B) 8.78 $\times$ 103 years 
C) 8.00 $\times$103 years 
D) 7.66 $\times$ 103 years 
E) 3.47 $\times$ 103 years 
A) 3.95 $\times$ 103 years 
B) 8.78 $\times$ 103 years 
C) 8.00 $\times$103 years 
D) 7.66 $\times$ 103 years 
E) 3.47 $\times$ 103 years

Question 10

A thermal neutron

Accepted Answer

A) produces electrons by thermionic emission. 
B) produces protons by thermionic emission. 
C) ionizes atoms by an increase in thermal energy. 
D) creates an electron-positron pair by an increase in thermal energy. 
E) gains kinetic energy as often as it loses it at room temperature. 
A) produces electrons by thermionic emission. 
B) produces protons by thermionic emission. 
C) ionizes atoms by an increase in thermal energy. 
D) creates an electron-positron pair by an increase in thermal energy. 
E) gains kinetic energy as often as it loses it at room temperature.

Question 11

The sodium atom has an atomic number of 11 and an atomic weight of 23.The neutral atom contains

Accepted Answer

A) 11 neutrons and 12 protons. 
B) 11 protons and 12 neutrons. 
C) 12 electrons and 11 neutrons. 
D) 23 protons and 12 electrons. 
E) 23 electrons and 12 neutrons. 
A) 11 neutrons and 12 protons. 
B) 11 protons and 12 neutrons. 
C) 12 electrons and 11 neutrons. 
D) 23 protons and 12 electrons. 
E) 23 electrons and 12 neutrons.

Question 12

Which of these nuclear reactions is possible?

Accepted Answer

A)    
B)    
C)    
D)    
E) None of these is possible. 
A)    
B)    
C)    
D)    
E) None of these is possible.

Question 13

As   decays to stable   ,you expect to observe

Accepted Answer

A) 16 $\alpha$ particles and 6 $\beta$- particles. 
B) 8 $\alpha$ particles and 6 $\beta$- particles. 
C) 6 $\alpha$ particles and no $\beta$- particles. 
D) 8 $\alpha$ particles and 6 $\beta$+ particles. 
E) 6 $\alpha$ particles and 2 $\beta$- particles. 
A) 16 $\alpha$ particles and 6 $\beta$- particles. 
B) 8 $\alpha$ particles and 6 $\beta$- particles. 
C) 6 $\alpha$ particles and no $\beta$- particles. 
D) 8 $\alpha$ particles and 6 $\beta$+ particles. 
E) 6 $\alpha$ particles and 2 $\beta$- particles.

Question 14

The intensity of gamma rays passing through a material as a function of thickness,x is given by   where n is the number of atoms per cm3 and  $\sigma$ is the absorption cross section.It is observed that the intensity of gamma rays of a particular energy is reduced by half when they passed through 1 cm of lead.What is the thickness of lead needed to reduce the intensity to a quarter?

Accepted Answer

A) 1.0 cm 
B) 1.5 cm 
C) 2.0 cm 
D) 3.0 cm 
E) 4.0 cm 
A) 1.0 cm 
B) 1.5 cm 
C) 2.0 cm 
D) 3.0 cm 
E) 4.0 cm

Question 15

A certain radioactive element has a half-life of 20 d.The time it will take for 7/8 of the atoms originally present to disintegrate is

Accepted Answer

A) 20 d 
B) 40 d 
C) 60 d 
D) 80 d 
E) 100 d 
A) 20 d 
B) 40 d 
C) 60 d 
D) 80 d 
E) 100 d

Question 16

The half-life of radium is about 1600 y.If you have 1.00 g of radium today,the amount remaining in 1000 y will be approximately

Accepted Answer

A) 625 mg 
B) 958 mg 
C) 707 mg 
D) 841 mg 
E) 649 mg 
A) 625 mg 
B) 958 mg 
C) 707 mg 
D) 841 mg 
E) 649 mg

Question 17

The energy at which the   endothermic reaction takes place is

Accepted Answer

A) 1.19 MeV 
B) 0.925 MeV 
C) 1.52 MeV 
D) 1.28 MeV 
E) 9.25 MeV 
A) 1.19 MeV 
B) 0.925 MeV 
C) 1.52 MeV 
D) 1.28 MeV 
E) 9.25 MeV

Question 18

Estimate the mass density of the nucleus of an atom.

Accepted Answer

A) 103 kg/m3 
B) 106 kg/m3 
C) 109 kg/m3 
D) 1014 kg/m3 
E) 1017 kg/m3 
A) 103 kg/m3 
B) 106 kg/m3 
C) 109 kg/m3 
D) 1014 kg/m3 
E) 1017 kg/m3

Question 19

The following fusion reaction occurs in the Sun:   The masses of the nuclei are   The energy released or absorbed by the reaction is

Accepted Answer

A) 920 MeV,absorbed 
B) 1.6 MeV,absorbed 
C) 920 MeV,released 
D) 1.6 MeV,released 
E) 270 MeV,released 
A) 920 MeV,absorbed 
B) 1.6 MeV,absorbed 
C) 920 MeV,released 
D) 1.6 MeV,released 
E) 270 MeV,released

Question 20

Many elements show resonances in neutron capture.What are these resonances?

Accepted Answer

A) especially large Q values for each neutron capture 
B) certain incident energies at which neutrons are most readily captured 
C) especially large N values resulting from the capture of many neutrons 
D) certain incident energies at which neutrons are least readily captured 
E) certain incident angles at which neutrons are most readily captured 
A) especially large Q values for each neutron capture 
B) certain incident energies at which neutrons are most readily captured 
C) especially large N values resulting from the capture of many neutrons 
D) certain incident energies at which neutrons are least readily captured 
E) certain incident angles at which neutrons are most readily captured

Exam 40: Nuclear Physics

The word isotopes describes elements that have

In what type of radioactive decay are the mass numbers of the parent and daughter nuclei the same?

About 200 MeV of energy is released in the average fission reaction.Most of this energy is

The nuclear radius of is approximately

The fact that most α\alphaα emitters show a group of discrete α\alphaα -particle energies,rather than a single energy,can best be explained by which of the following?

The unifying concepts in physics are the conservation laws.To preserve these laws in nuclear processes,it became necessary to postulate the existence of

A radioactive source has a half-life of 2 min.At time t = 0 it is placed near a detector and the counting rate is observed to be 3000 counts/s.If the detection efficiency is 25%,how many radioactive nuclei are there at time t = 0?

A sphere of radius r1 collides with a sphere of radius r2.The cross section for a contact collision is

An old piece of dead wood contains 38% of the 14C abundance of a living sample.How old is it? (The half-life of 14C is 5730 years.)

A thermal neutron

The sodium atom has an atomic number of 11 and an atomic weight of 23.The neutral atom contains

Which of these nuclear reactions is possible?

As decays to stable ,you expect to observe

A certain radioactive element has a half-life of 20 d.The time it will take for 7/8 of the atoms originally present to disintegrate is

The half-life of radium is about 1600 y.If you have 1.00 g of radium today,the amount remaining in 1000 y will be approximately

The energy at which the endothermic reaction takes place is

Estimate the mass density of the nucleus of an atom.

The following fusion reaction occurs in the Sun: The masses of the nuclei are The energy released or absorbed by the reaction is

Many elements show resonances in neutron capture.What are these resonances?

Systems of Measurement

Motion in One Dimension

Motion in Two and Three Dimensions

Newtons Laws

Applications of Newtons Laws

Work and Energy

Conservation of Energy

Systems of Particles and Conservation of Linear Momentum

Rotation

Conservation of Angular Momentum

Gravity

Static Equilibrium and Elasticity

Fluids

Oscillations

Wave Motion

Superposition and Standing Waves

Temperature and the Kinetic Theory of Gases

Heat and the First Law of Thermodynamics

The Second Law of Thermodynamics

Thermal Properties and Processes

The Electric Field I: Discrete Charge Distributions

The Electric Field Ii: Continuous Charge Distributions

Electric Potential

Capacitance

Electric Current and Direct-Current Circuits

The Magnetic Field

Sources of the Magnetic Field

Magnetic Induction

Alternating-Current Circuits

Maxwells Equations and Electromagnetic Waves

Properties of Light

Optical Images

Interference and Diffraction

Wave Particle Duality and Quantum Physics

Applications of the Schrodinger Equation

Atoms

Molecules

Solids and the Theory of Conduction

Relativity

Elementary Particles and the Beginning of the Universe

Filters

The fact that most $\alpha$ emitters show a group of discrete $\alpha$ -particle energies,rather than a single energy,can best be explained by which of the following?

A sphere of radius r₁ collides with a sphere of radius r₂.The cross section for a contact collision is

An old piece of dead wood contains 38% of the ¹⁴C abundance of a living sample.How old is it? (The half-life of ¹⁴C is 5730 years.)