Deck 28: Quantum Physics

Question 1

A particle with non-zero kinetic energy will

A) always have the same wavelength as the same energy photon.
B) always have a greater wavelength than the same energy photon.
C) always have a shorter wavelength than the same energy photon.
D) sometimes have a greater wavelength than the same energy photon.
E) sometimes have a shorter wavelength than the same energy photon.

Answer 1

always have a shorter wavelength than the same energy photon.

Question 2

A bullet is fired from a rifle.The end of the barrel is a circular aperture.Is diffraction a measurable effect?

A) yes
B) no,because the de Broglie wavelength of the bullet is too large relative to the aperture
C) yes,because the aperture may be a slit or circular aperture
D) no,because the de Broglie wavelength of the bullet is too small relative to the aperture

Answer 2

no,because the de Broglie wavelength of the bullet is too small relative to the aperture

Question 3

How are the circumference,C,of the ground-state orbit of the electron in hydrogen and the de Broglie wavelength , $\lambda$ , related?

A) $\lambda$ = C
B) $\pi$$\lambda$ = C
C) 2 $\pi$$\lambda$ = C
D) $\lambda$ = $\pi$ C
E) $\lambda$ = 2 $\pi$ C

Answer 3

$\lambda$ = C

Question 4

What is the wavelength of an electron in the n = 2 state of the hydrogen atom?

A) 5.20 $\times$ 10^-11 m
B) 1.66 $\times$ 10^-10 m
C) 3.32 $\times$ 10^-10 m
D) 6.65 $\times$ 10^-10 m
E) 1.33 $\times$ 10^-9 m

Question 5

What is the wavelength of a neutron with kinetic energy 44.0 keV?

A) 56.4 pm
B) 0.137 pm
C) 0.166 pm
D) 2.83 pm
E) 5.11 pm

Question 6

What accelerating potential in an electron microscope would give electrons a wavelength 1.00 $\times$ 10^-10 m?

A) 37.5 V
B) 75.0 V
C) 150 V
D) 300 V

Question 7

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

A) 0.40 kg objects don't have wavelengths
B) 10 m
C) 0.10 m
D) 6.6 $\times$ 10^-35 m
E) 0.53 $\times$ 10^-10 m

Question 8

An electron and a neutron have the same de Broglie wavelength,therefore

A) the electron and neutron have the same kinetic energy but the electron has the higher speed.
B) the electron has a lower speed and smaller kinetic energy.
C) the electron has higher kinetic energy and higher speed.
D) the electron has smaller kinetic energy and higher speed.

Question 9

The first observation of electron diffraction was done by

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

Question 10

What is the energy of a photon that has the same wavelength as an electron with energy 1.60 $\times$ 10^-15 J?

A) 10.0 keV
B) 101 keV
C) 55.3 keV
D) 5.53 keV
E) 6.77 keV

Question 11

If an electron is accelerated from rest through a potential difference of 100 V,what is its de Broglie wavelength?

A) 2.55 $\times$ 10^-9 m
B) 1.23 $\times$ 10^-10 m
C) 0.529 $\times$ 10^-10 m
D) 8.67 $\times$ 10^-9 m
E) 1.20 $\times$ 10^-15 m

Question 12

Which of the following experiments demonstrate the particle properties of light?

A) diffraction
B) interference
C) photoelectric effect
D) refraction

Question 13

The probability of finding a particle with wave function $\Psi$ in an interval $\Delta$ x is given by

A) $\Psi$ .
B) $\Psi$ $\Delta$ x.
C) $\Psi$ ( $\Delta$ x)².
D) $\Psi$ ² $\Delta$ x.
E) $\Psi$ ² ( $\Delta$ x)².

Question 14

How is the circumference,C_n,of the n^th orbit in hydrogen and the de Broglie wavelength, $\lambda$ _n,of the n^th orbit related?

A) $\lambda$ _n = C_n
B) n $\lambda$ _n = C_n
C) $\lambda$ _n/n= C_n
D) n² $\lambda$ _n = C_n
E) 2 $\pi$$\lambda$ _n = C_n

Question 15

If the momentum of a particle is doubled,what happens to its de Broglie wavelength?

A) it doubles
B) it halves
C) it slightly more than doubles
D) it becomes slightly less than half
E) it decreases by a factor of 2^-1/2

Question 16

The ratio of the de Broglie wavelength of the electron in the n = 4 orbit in hydrogen to the wavelength in the n = 1 orbit is

A) 1.
B) 2.
C) 4.
D) 16.
E) 0.25.

Question 17

Which of the following experiments demonstrate the wave properties of light?

A) photoelectric effect
B) Compton effect
C) diffraction effect
D) pair production

Question 18

Quantum mechanics tells us that the probability of finding the electron in hydrogen at a distance between r and r + $\Delta$ r in the ground state is greatest at a distance _____ a₀,where a₀ is the Bohr radius.

A) 0.707
B) 1.00
C) 1.41
D) 2.00
E) 3.00^1/2

Question 19

What is the wavelength of an electron with energy 1.60 $\times$ 10^-15 J?

A) 61.2 nm
B) 612 nm
C) 1.20 fm
D) 13.7 pm
E) 12.3 pm

Question 20

Considering only the effect of diffraction,what is the smallest structure resolvable using a 12keV electron microscope?

A) 1.15 $\times$ 10¹¹ m
B) 1.23 $\times$ 10¹¹ m
C) 1.12 $\times$ 10¹¹ m
D) 1.14 $\times$ 10¹¹ m

Question 21

The statistical interpretation associated with the wave function originated with

A) Born.
B) Bohr.
C) Einstein.
D) Schrödinger.
E) Planck.

Question 22

For a particle in a finite box,which of the following is not true?

A) The energies are quantized for bound states.
B) The bound-state wave functions at the walls do not have to be zero.
C) The wave function can exist outside the walls.
D) There is the same number of bound states in a finite box as in a box with infinite walls.
E) None of these statements are true.

Question 23

According to the uncertainty principle,halving the uncertainty in position is accompanied by __________ the minimum uncertainty in momentum.

A) halving
B) quartering
C) doubling
D) quadrupling
E) no change in

Question 24

The uncertainty principle was formulated by

A) Einstein.
B) Bohr.
C) Heisenberg.
D) Planck.
E) Dirac.

Question 25

An alternate version of the uncertainty principle exchanges the uncertainties in position and momentum with uncertainties in __________ and time interval.

A) angular momentum
B) charge
C) angle
D) energy
E) wavelength

Question 26

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

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

Question 27

To determine the state of the electron in the hydrogen atom requires _____ quantum number(s).

A) 1
B) 2
C) 3
D) 4
E) 5

Question 28

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

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 29

For the principle quantum number n = 4,how many values can the orbital quantum number have?

A) 9
B) 5
C) 4
D) 3
E) 32

Question 30

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

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

Question 31

Which one of the following is true?

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 its ground state is zero.

Question 32

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

A) 1.1 $\times$ 10^-27 kg·m/s
B) 1.8 $\times$ 10^-28 kg·m/s
C) 8.8 $\times$ 10^-29 kg·m/s
D) 1.2 $\times$ 10^-32 kg·m/s
E) 1.8 $\times$ 10^-32 kg·m/s

Question 33

How do the energy level spacings change for a particle in a box when the box is made longer?

A) decrease
B) stay the same
C) increase
D) halved

Question 34

The fundamental equation of quantum mechanics is known as the ________ equation.

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

Question 35

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

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

Question 36

If a string of length L,fixed at both ends,is made to resonate at its lowest possible frequency,what is the wavelength associated with that resonance?

A) L
B) 2L
C) L/2
D) 0.707L
E) 1.414L

Question 37

How do the energy level spacings for a particle in a box change when the box is made longer?

A) The spacings do not change.
B) The spacings increase.
C) The spacings decrease.
D) There is insufficient information to answer this question.

Question 38

If a particle in a box has a ground-state energy of 10.0 eV,what is the energy of the 4^th excited state?

A) 20.0 eV
B) 40.0 eV
C) 160 eV
D) 50.0 eV
E) 250 eV

Question 39

In a 3d subshell,what are the possible values for the magnetic quantum number?

A) 3
B) 3,-3
C) 3,2,1,0
D) 2,1,0,-1,-2
E) 2,-2

Question 40

For a particle in a 1-dimensional box,what happens to the zero-point energy if the width of the box is halved?

A) nothing,it remains at zero
B) it doubles
C) it halves
D) it quadruples
E) it quarters

Question 41

The exclusion principle

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

Question 42

Alkali metals have how many electrons past the noble gas configuration?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 43

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

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

Question 44

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

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

Question 45

A carbon dioxide laser emits photons of 10.6 $\mu$ m wavelength.How many photons per second are emitted by a 10.0 kW CO₂ laser?

A) 4.27 $\times$ 10²¹
B) 5.39 $\times$ 10³⁰
C) 3.17 $\times$ 10¹⁸
D) 5.34 $\times$ 10²³
E) 6.20 $\times$ 10²³

Question 46

What is the typical thermal energy of an electron in a solid at room temperature?

A) 0.00
B) 0.0010 eV
C) 0.025 eV
D) 0.27 eV
E) 1.0 eV

Question 47

If a solid has a half-filled valence band,which of the following would it be?

A) a conductor
B) an insulator
C) a semiconductor
D) a p-type semiconductor
E) an n-type semiconductor

Question 48

For the principle quantum number n = 5,what is the greatest number of values the spin quantum number can have?

A) 5
B) 25
C) 11
D) 2
E) 4

Question 49

The configuration 1s²2s²2p⁶3s²3p¹ is for what element?

A) B
B) F
C) Ne
D) Al
E) Cr

Question 50

For an orbital angular momentum quantum number of 4,what is the magnitude of the orbital angular momentum?

A) 4 h
B) 3 h
C) $\sqrt{6}$ h
D) $\sqrt{12}$ h
E) $\sqrt{20}$ h

Question 51

A situation known as "population inversion" is needed for lasing action.What does "population inversion" mean?

A) Electrons are in the -1/2 state.
B) Excited atoms must be at the top of the laser tube.
C) Excited atoms must be at the bottom of the laser tube.
D) The number of excited states that are to emit photons are in greater number than the lower states at which the transition is ending.
E) The number of lower states are in greater number than the upper states participating in the lasing action.

Question 52

Optical pumping of a ruby laser is done with photons absorbed at energy 2.25 eV.The laser light consists of photons of energy 1.79 eV in a transition that goes to ground.What is the energy of the transition from the pumped stated to the lasing state?

A) 2.25 eV
B) 1.79 eV
C) 4.04 eV
D) 0.460 eV
E) 1.30 eV

Question 53

Except for helium,the outer subshell of a noble gas has what electron configuration?

A) s²p⁴
B) s²p⁶
C) d²s²
D) d⁶p²
E) s¹p⁴

Question 54

What is the orbital angular momentum quantum number for a d subshell?

A) 10
B) 7
C) 4
D) 3
E) 2

Question 55

Excited atomic states that last for a relatively long time are called

A) laser states.
B) metastable states.
C) amplification states.
D) radiation states.
E) cascading states.

Question 56

In the He-Ne laser,the lasing transition goes from the 20.66 eV state in Ne to a lower state.The wavelength of the laser photons is 633.0 nm.What is the lower state of the lasing transition?

A) the He ground state
B) the Ne ground state
C) the 20.61 eV excited stated of He
D) the 18.70 eV excited state of Ne
E) the 4.660 eV excited state of Ne

Question 57

What letter stands for an orbital with orbital quantum number 5?

A) h
B) g
C) f
D) d
E) p

Question 58

An atom has subshells 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰ in the ground state.What is its atomic number?

A) 10
B) 18
C) 20
D) 30
E) More information is needed.

Question 59

In lasers,YAG stands for

A) yellow argon gold.
B) yearly age group.
C) yttrium assisted gain.
D) yttrium aluminum garnet.
E) yttrium antimony gain.

Question 60

How many states are in the n = 4 shell?

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

Question 61

Each element in a column of the periodic table

A) has the same size.
B) has the same nuclear properties.
C) has the same electron configuration.
D) has the same nuclear charge.

Question 62

The more precisely the position of a particle is known,

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 deBroglie wavelength is.

Question 63

As the principal quantum number of the Hydrogen atom increases,what does the spacing between adjacent energy levels do?

A) Decreases
B) Increases
C) Stays the same

Question 64

A baseball has a mass of 0.15 kg.If pitched at 40.0 m/s with a relative uncertainty of 1%,how uncertain is its position?

A) 9.1 $\times$ 10^-34 m
B) 5.7 $\times$ 10^-34 m
C) 1.8 $\times$ 10^-34 m
D) 6.3 $\times$ 10^-33 m

Question 65

What is the full multiplicity of the n = 3 level of the H atom?

A) 18
B) 30
C) 16
D) 32
E) 9

Question 66

It is desired to use an electron microscope to study features in a virus that are about 0.25 nm.What accelerating voltage is needed for the electrons used in this microscope?

A) 96 V
B) 48 V
C) 24 V
D) 5 V

Question 67

How many different spin orientations can an electron have in a given orbital?

A) 2
B) 1
C) Any number
D) 4

Question 68

The uncertainty in the position of a proton is 250 pm.What is the minimum velocity of the proton when its position has been measured to this precision?

A) 0.29c
B) 0.10c
C) 0.39c
D) 0.21c

Question 69

The deBroglie wavelength for a particle indicates its

A) position
B) momentum
C) mass
D) physical extent in space

Question 70

For the first excited state (n = 2) of the particle in a box of width L,what is the uncertainty in momentum?

A) $\pi$$\ddot{A}$$\S$ / 2
B) 3 $\pi$$\ddot{A}$$\S$ / 2
C) $\ddot{A}$$\S$
D) $\pi$$\ddot{A}$$\S$

Question 71

The uncertainty in the position of a proton is 250 pm.What is the minimum kinetic energy of the proton when its position has been measured to this precision?

A) 41 MeV
B) 83 MeV
C) 21 MeV
D) 5.2 MeV

Question 72

A beam of neutrons (m = 939.6 MeV/c²) of momentum 12 keV is passed through a single slit of width 0.10 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.If the distance between the slit and a projection screen onto which the neutrons are projected is 1.5 m,what is the expected width of the neutron distribution on the projection screen in the transverse direction?

A) 155 cm
B) 12 cm
C) 25 cm
D) 50 cm

Question 73

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

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