Question 1

The de Broglie wavelength for a particle is related to its

Accepted Answer

A)  position. 
B)  momentum. 
C)  mass. 
D)  charge. 
A)  position. 
B)  momentum. 
C)  mass. 
D)  charge.

Question 2

Quantum-mechanical wave functions are solutions of what equation?

Accepted Answer

A)  the Heisenberg equation 
B)  the Bohr equation 
C)  the Born equation 
D)  the Schrödinger equation 
E)  the de Broglie equation 
A)  the Heisenberg equation 
B)  the Bohr equation 
C)  the Born equation 
D)  the Schrödinger equation 
E)  the de Broglie equation

Question 3

If an element has a band gap of 1 eV between a filled valence band and an empty conduction band, it would be classified (at room temperature) as a(n)

Accepted Answer

A)  insulator. 
B)  conductor. 
C)  resistor. 
D)  semiconductor. 
E)  reactor. 
A)  insulator. 
B)  conductor. 
C)  resistor. 
D)  semiconductor. 
E)  reactor.

Question 4

If the ground-state configuration of an atom is 1s22s22p4, what is the atomic number of the atom?

Accepted Answer

A)  14 
B)  10 
C)  8 
D)  4 
E)  3 
A)  14 
B)  10 
C)  8 
D)  4 
E)  3

Question 5

Which one of the following is true?

Accepted Answer

A)  The principal quantum number of the electron in a hydrogen atom does not affect its energy. 
B)  The orbital angular momentum quantum number of an electron state is always less than the principal quantum number. 
C)  The electron spin quantum number can take on any one of four different values. 
D)  The principal quantum number of an electron in the ground state is zero. 
A)  The principal quantum number of the electron in a hydrogen atom does not affect its energy. 
B)  The orbital angular momentum quantum number of an electron state is always less than the principal quantum number. 
C)  The electron spin quantum number can take on any one of four different values. 
D)  The principal quantum number of an electron in the ground state is zero.

Question 6

A particle in a box with ground-state energy E1 = 4.0 eV undergoes a transition from the third excited state to the second excited state, emitting a photon in the process. What is the energy of the photon?

Accepted Answer

A)  4.0 eV 
B)  16 eV 
C)  20 eV 
D)  28 eV 
E)  26 eV 
A)  4.0 eV 
B)  16 eV 
C)  20 eV 
D)  28 eV 
E)  26 eV

Question 7

Instead of the usual position-momentum formulation, an alternate version of the uncertainty principle relates what two quantities?

Accepted Answer

A)  mass and angular momentum 
B)  charge and electric field 
C)  angle and position 
D)  energy and time 
E)  wavelength and frequency 
A)  mass and angular momentum 
B)  charge and electric field 
C)  angle and position 
D)  energy and time 
E)  wavelength and frequency

Question 8

If the orbital angular momentum quantum number is 3, how many values are possible for the orbital magnetic quantum number?

Accepted Answer

A)  9 
B)  7 
C)  5 
D)  4 
E)  3 
A)  9 
B)  7 
C)  5 
D)  4 
E)  3

Question 9

Who first observed wavelike interference and diffraction effects in the scattering of electrons by a crystalline target?

Accepted Answer

A)  J. J. Thompson 
B)  Louis de Broglie 
C)  Niels Bohr 
D)  Einstein and Planck 
E)  Davisson and Germer 
A)  J. J. Thompson 
B)  Louis de Broglie 
C)  Niels Bohr 
D)  Einstein and Planck 
E)  Davisson and Germer

Question 10

The Pauli exclusion principle

Accepted Answer

A)  excludes electrons from atomic nuclei. 
B)  means that no two electrons in an atom can have the same orbit. 
C)  implies that no two electrons in an atom can have identical sets of quantum numbers. 
D)  excludes protons from electron orbits. 
A)  excludes electrons from atomic nuclei. 
B)  means that no two electrons in an atom can have the same orbit. 
C)  implies that no two electrons in an atom can have identical sets of quantum numbers. 
D)  excludes protons from electron orbits.

Question 11

The energy of an electron in an atom depends primarily on

Accepted Answer

A)  the spin magnetic quantum number ms. 
B)  the principal quantum number n. 
C)  the orbital angular momentum quantum number l. 
D)  the orbital magnetic quantum number ml. 
A)  the spin magnetic quantum number ms. 
B)  the principal quantum number n. 
C)  the orbital angular momentum quantum number l. 
D)  the orbital magnetic quantum number ml.

Question 12

If light of wavelength 600 nm is used to locate an electron to within one wavelength of the light, what is the minimum uncertainty in the electron's momentum?

Accepted Answer

A)  1.1 × 10−27 kg·m/s 
B)  1.8 × 10−28 kg·m/s 
C)  8.8 × 10−29 kg·m/s 
D)  1.2 × 10−32 kg·m/s 
E)  1.8 × 10−32 kg·m/s 
A)  1.1 × 10−27 kg·m/s 
B)  1.8 × 10−28 kg·m/s 
C)  8.8 × 10−29 kg·m/s 
D)  1.2 × 10−32 kg·m/s 
E)  1.8 × 10−32 kg·m/s

Question 13

How many states are in the n = 4 shell?

Accepted Answer

A)  4 
B)  9 
C)  16 
D)  18 
E)  32 
A)  4 
B)  9 
C)  16 
D)  18 
E)  32

Question 14

According to the uncertainty principle, if the uncertainty in position is reduced by a factor of two, the minimum uncertainty in momentum

Accepted Answer

A)  halves. 
B)  quarters. 
C)  doubles. 
D)  quadruples. 
E)  doesn't change. 
A)  halves. 
B)  quarters. 
C)  doubles. 
D)  quadruples. 
E)  doesn't change.

Question 15

The more precisely the position of a particle is known,

Accepted Answer

A)  the more precisely its momentum can be known. 
B)  the more precisely its energy can be known. 
C)  the less precisely its momentum can be known. 
D)  the shorter its de Broglie wavelength is. 
A)  the more precisely its momentum can be known. 
B)  the more precisely its energy can be known. 
C)  the less precisely its momentum can be known. 
D)  the shorter its de Broglie wavelength is.

Question 16

Which of these statements about electron energy levels in hydrogen atoms is true?

Accepted Answer

A)  An electron with a positive total energy is a bound electron. 
B)  The orbital angular momentum of an electron in the ground state is zero. 
C)  An electron in the hydrogen atom is best represented as a traveling wave. 
D)  An electron in state n can make transitions only to the state n + 1 or n − 1. 
A)  An electron with a positive total energy is a bound electron. 
B)  The orbital angular momentum of an electron in the ground state is zero. 
C)  An electron in the hydrogen atom is best represented as a traveling wave. 
D)  An electron in state n can make transitions only to the state n + 1 or n − 1.

Question 17

A beam of neutrons (m = 939.6 MeV/c2) of momentum 12 keV/c is passed through a single slit of width 0.1 nm. As a result of this, the neutron beam acquires an uncertainty in the component of the momentum that is transverse to the beam direction. The distance between the slit and a screen onto which the neutrons are projected is 1.5 m. Using the uncertainty principle, estimate the expected width of the neutron distribution on the screen.

Accepted Answer

A)  0.1 mm 
B)  1 cm 
C)  50 cm 
D)  5 m 
A)  0.1 mm 
B)  1 cm 
C)  50 cm 
D)  5 m

Question 18

What is the de Broglie wavelength of a 0.40 kg object moving at 25 m/s?

Accepted Answer

A)  0.40 kg objects don't have wavelengths 
B)  10 m 
C)  0.10 m 
D)  6.6 × 10−35 m 
E)  0.53 × 10−10 m 
A)  0.40 kg objects don't have wavelengths 
B)  10 m 
C)  0.10 m 
D)  6.6 × 10−35 m 
E)  0.53 × 10−10 m

Question 19

As the principal quantum number for a particle in the infinite square well increases, what happens to the spacing between adjacent energy levels?

Accepted Answer

A)  It decreases. 
B)  It stays the same. 
C)  It increases. 
A)  It decreases. 
B)  It stays the same. 
C)  It increases.

Question 20

Using the energy-time version of the uncertainty principle, estimate the uncertainty in the energy of a state with lifetime of 10−9 s.

Accepted Answer

A)  10−2 eV 
B)  10−7 eV 
C)  10−12 eV 
D)  10−15 eV 
E)  10−18 eV 
A)  10−2 eV 
B)  10−7 eV 
C)  10−12 eV 
D)  10−15 eV 
E)  10−18 eV

Exam 28: Quantum Physics

The de Broglie wavelength for a particle is related to its

Quantum-mechanical wave functions are solutions of what equation?

If an element has a band gap of 1 eV between a filled valence band and an empty conduction band, it would be classified (at room temperature) as a(n)

If the ground-state configuration of an atom is 1s22s22p4, what is the atomic number of the atom?

Which one of the following is true?

A particle in a box with ground-state energy E1 = 4.0 eV undergoes a transition from the third excited state to the second excited state, emitting a photon in the process. What is the energy of the photon?

Instead of the usual position-momentum formulation, an alternate version of the uncertainty principle relates what two quantities?

If the orbital angular momentum quantum number is 3, how many values are possible for the orbital magnetic quantum number?

Who first observed wavelike interference and diffraction effects in the scattering of electrons by a crystalline target?

The Pauli exclusion principle

The energy of an electron in an atom depends primarily on

If light of wavelength 600 nm is used to locate an electron to within one wavelength of the light, what is the minimum uncertainty in the electron's momentum?

How many states are in the n = 4 shell?

According to the uncertainty principle, if the uncertainty in position is reduced by a factor of two, the minimum uncertainty in momentum

The more precisely the position of a particle is known,

Which of these statements about electron energy levels in hydrogen atoms is true?

What is the de Broglie wavelength of a 0.40 kg object moving at 25 m/s?

As the principal quantum number for a particle in the infinite square well increases, what happens to the spacing between adjacent energy levels?

Using the energy-time version of the uncertainty principle, estimate the uncertainty in the energy of a state with lifetime of 10−9 s.

Introduction

Motion Along a Line

Motion in a Plane

Force and Newtons Laws of Motion

Circular Motion

Conservation of Energy

Linear Momentum

Torque and Angular Momentum

Fluids

Elasticity and Oscillations

Waves

Sound

Temperature and the Ideal Gas

Heat

Thermodynamics

Electric Forces and Fields

Electric Potential

Electric Current and Circuits

Magnetic Forces and Fields

Electromagnetic Induction

Alternating Current

Electromagnetic Waves

Reflection and Refraction of Light

Optical Instruments

Interference and Diffraction

Relativity

Early Quantum Physics and the Photon

Nuclear Physics

Particle Physics

Filters

If the ground-state configuration of an atom is 1s²2s²2p⁴, what is the atomic number of the atom?

A particle in a box with ground-state energy E₁ = 4.0 eV undergoes a transition from the third excited state to the second excited state, emitting a photon in the process. What is the energy of the photon?

Using the energy-time version of the uncertainty principle, estimate the uncertainty in the energy of a state with lifetime of 10⁻⁹ s.