Deck 37: Early Quantum Theory and Models of the Atom

Question 1

In the spectrum of a blackbody, the wavelength of peak intensity

A)decreases as temperature increases.
B)is 0.029 m.
C)is 0.0029 m.
D)increases as temperature increases.
E)is independent of temperature.

Answer 1

decreases as temperature increases.

Question 2

Unlike other particles, photons have a finite momentum even though they have no mass.

Answer 2

True

Question 3

The rest mass of a photon is zero.

Answer 3

True

Question 4

The energy of an ultraviolet photon is more than the energy of an infrared photon.

Question 5

Blackbody radiation is from a body that

A)does not emit radiation in the visible.
B)is black.
C)deflects all radiation falling on it.
D)absorbs all radiation falling on it.
E)is actually white.

Question 6

In the spectrum of white light which one of the following colors corresponds to the highest temperature?

A)Yellow
B)Violet
C)Green
D)Red
E)Orange

Question 7

One star appears blue-white while another appears yellow-orange. If this is caused by temperature difference, then

A)the stars are the same brightness.
B)the yellow-orange star is hotter.
C)the blue-white star is brighter.
D)the blue-white star is hotter.
E)the yellow-orange star is brighter.

Question 8

The behavior of blackbody radiation was poorly explained until ________ produced an adequate theory.

A)Wien
B)Bohr
C)Planck
D)Jeans
E)Rayleigh

Question 9

Electrons come in discrete units of well defined mass and charge, but they also have wave properties.

Question 10

In the spectrum of white light which one of the following colors corresponds to the lowest temperature?

A)Yellow
B)Blue
C)Red
D)Green
E)Orange

Question 11

What is a photon?

A)an electron in an excited state
B)a small packet of electromagnetic energy that has particle-like properties
C)one form of a nucleon, one of the particles that makes up the nucleus
D)an electron that has been made electrically neutral
E)a proton that has been made electrically neutral

Question 12

The Compton effect justifies that light acts as photons.

Question 13

A blackbody is an ideal system that

A)absorbs 100% of the light incident upon it, but cannot emit light of its own (i.e., a "black" body).
B)emits 100% of the light it generates, but cannot absorb radiation of its own.
C)either absorbs 100% of the light incident upon it, or emits 100% of the radiation it generates.
D)absorbs 50% of the light incident upon it, and emits 50% of the radiation it generates.
E)absorbs 95% of the light incident upon it, and emits 5% of the radiation it generates.

Question 14

The energy of a photon depends on

A)its amplitude.
B)its velocity.
C)its frequency.
D)its mass.
E)none of the given answers

Question 15

Planck's constant

A)sets an upper limit to the amount of energy that can be absorbed or emitted.
B)sets a lower limit to the amount of energy that can be absorbed or emitted.
C)relates mass to energy.
D)relates mass to velocity.
E)none of the given answers

Question 16

A blackbody is a perfect emitter of the radiation it generates.

Question 17

The de Broglie wavelength is inversely proportional to the momentum of the particle.

Question 18

The distribution of energy in the blackbody radiation depends upon the material from which the blackbody is constructed.

Question 19

An ideal blackbody absorbs all of the light that is incident on it.

Question 20

The ratio of energy to frequency for a given photon gives

A)its amplitude.
B)its velocity.
C)its wavelength.
D)Planck's constant.
E)its work function.

Question 21

What advantage might an electron microscope have over a light microscope?

A)Electrons are more powerful.
B)Shorter wavelengths are possible.
C)Longer wavelengths are possible.
D)none of the given answers

Question 22

A proton and an electron are both accelerated to the same final speed. If λ_p is the de Broglie wavelength of the proton and λ_e is the de Broglie wavelength of the electron, then

A)λ_p > λ_e.
B)λ_p = λ_e.
C)λ_p < λ_e.
D)Not enough data to answer this question.

Question 23

A proton and an electron are both accelerated to the same final kinetic energy. If λ_p is the de Broglie wavelength of the proton and λ₃ is the de Broglie wavelength of the electron, then

A)λ_p > λ_e.
B)λ_p = λ_e.
C)λ_p < λ_e.
D)Not enough data to answer this question.

Question 24

In a Compton scattering experiment, what scattering angle produces the greatest change in wavelength?

A)0°
B)45°
C)90°
D)180°
E)none of the given answers

Question 25

The Compton effect demonstrates

A)relativistic formulation works well.
B)consistent explanations of scattered photon shift in wavelength.
C)light acts as photons.
D)all of the above.
E)none of the above.

Question 26

A beam of red light and a beam of violet light each deliver the same power on a surface. For which beam is the number of photons hitting the surface per second the greatest?

A)the red beam
B)the violet beam
C)The number of photons per second is the same for both beams.
D)This cannot be answered without knowing just what the light intensity is.

Question 27

Photons of visible wavelengths are shone on a surface starting with one end of the spectrum and gradually proceeding to the other end. When 589 nm is reached, electrons start coming out of the surface. Which of the following is true?

A)The spectrum scan started at the blue end.
B)Electrons would not be ejected at this wavelength for any material.
C)The spectrum scan started at the red end.
D)The spectrum scan could have started at either end.
E)none of the above

Question 28

You perform Compton scattering experiments with X-rays of a fixed wavelength. In one experiment you scatter the X-rays from free electrons. In the second experiment you scatter the X-rays from protons instead. For X-rays scattered under a given angle, the wavelength change

A)will be larger for scattering from protons.
B)will be the same for both cases.
C)will be larger for scattering from electrons.
D)depends on the actual wavelength of the X-rays.

Question 29

In the non-relativistic case, doubling the speed of an electron causes its wavelength to

A)double.
B)quadruple.
C)halve.
D)decrease by a factor of four.
E)triple.

Question 30

What scattering angle in the Compton effect produces the minimum change in frequency?

A)45°
B)90°
C)0°
D)180°
E)270°

Question 31

In the Compton effect, if a photon is scattered at a particular angle, the resulting shift in wavelength for the scattered photon

A)is the same for all incident energy photons.
B)is greater for a higher energy incident photon.
C)depends on the wavelength of the incident photon.
D)is never the same for incident energy photons.
E)is less for a higher energy incident photon.

Question 32

In the relativistic case, doubling the speed of an electron causes its wavelength to

A)double.
B)more than double.
C)halve.
D)decrease to less than one-half.
E)quadruple.

Question 33

When a proton passes through matter, it is possible for it to interact with the matter in such a way that an electron and a positron are produced; this interaction is referred to as

A)the photoelectric effect.
B)the Compton effect.
C)the de Broglie effect.
D)pair production.
E)none of the given answers

Question 34

A source of light is at a temperature of 1000°C. Its temperature is then increased to 2000°C, Increasing the temperature causes the peak intensity wavelength to

A)triple.
B)halve.
C)decrease but not quite halve.
D)double.
E)more than double.

Question 35

As a result of Compton scattering, the scattered photon has

A)a longer wavelength than the incident photon.
B)a wavelength 24 pm shorter than the incident photon.
C)the same wavelength as the incident photon.
D)a wavelength 32 pm shorter than the incident photon.
E)a shorter wavelength than the incident photon.

Question 36

A metal surface is illuminated with blue light and electrons are ejected at a given rate each with a certain amount of energy. If the intensity of the blue light is increased, electrons are ejected

A)at the same rate, but with more energy per electron.
B)at the same rate, but with less energy per electron.
C)at an increased rate with no change in energy per electron.
D)at a reduced rate with no change in energy per electron.

Question 37

As a particle travels faster, its de Broglie wavelength

A)increases.
B)decreases.
C)remains constant.
D)could be any of the given answers; it depends on other factors.

Question 38

In order for a photon to eject an electron from a metal's surface in the photoelectric effect, the photon's

A)frequency must be greater than a certain minimum value.
B)speed must be greater than a certain minimum value.
C)wavelength must be greater than a certain minimum value.
D)momentum must be zero.

Question 39

What happens to the frequency of the scattered X-rays as the scattering angle in the Compton effect decreases?

A)It stays the same.
B)It decreases.
C)It increases.
D)Not enough information

Question 40

Light of a given wavelength is used to illuminate the surface of a metal, however, no photoelectrons are emitted. In order to cause electrons to be ejected from the surface of this metal you should

A)use light of a longer wavelength.
B)use light of a shorter wavelength.
C)use light of the same wavelength but increase its intensity.
D)use light of the same wavelength but decrease its intensity.

Question 41

At what peak wavelength does an object at 37°C (98.6°F) radiate?

A)94 × 10^-6 m
B)9.4 × 10^-6 m
C)29 × 10^-6 m
D)7.8 × 10^-6 m
E)78 × 10^-6 m

Question 42

If a star has a peak intensity at 580 nm, what is its temperature?

A)2000 K
B)5000°F
C)2000°C
D)5000 K
E)5000°C

Question 43

Which one of the following is correct for the energy of a 620 nm beam of light?

A)1.60 × 10^-19 eV
B)2.10 × 10^-19 J
C)3.21 × 10^-19 J
D)1.60 × 10^-18 eV
E)3.21 × 10^-18 eV

Question 44

Bohr's quantum condition was

A)angular momentum is quantized.
B)energy is exchanged when changing state.
C)a photon is emitted as a quantum of energy
D)electron orbits are stationary states.
E)none of the above.

Question 45

What is the energy of a 633 nm photon?

A)0.32 eV
B)3.14 eV
C)5.1 eV
D)1.96 eV
E)0.51 eV

Question 46

What is the energy of a photon with a frequency of 6.60 × 10¹⁵ Hz?

A)27.3 eV
B)12.3 eV
C)18.1 eV
D)19.6 eV
E)6.60 eV

Question 47

What fraction of the total energy density in a cavity filled with black body radiation at 5000 K is in the range 5.80 × 10¹⁴ Hz and 5.85 × 10¹⁴ Hz?

A)5%
B)10%
C)1.5%
D)1%
E)25%

Question 48

If the hydrogen atom is in the n = 4 state, what is the largest number of photons that can be emitted as the atom goes back to the ground state?

A)0
B)4
C)2
D)3
E)1

Question 49

A photon has energy of 4.20 eV. To what wavelength does this energy correspond?

A)321 nm
B)103 nm
C)296 nm
D)412 nm
E)420 nm

Question 50

What is the energy of a photon of wavelength 3 cm?

A)82 eV
B)4.1 × 10^-5 eV
C)41 eV
D)4.1 × 10^-5 J
E)3 ergs

Question 51

A discrete spectrum is one that

A)only has wavelengths longer than the visible.
B)never yields a line spectrum.
C)yields a line spectrum.
D)has continuous wavelengths.
E)only has wavelengths in the visible.

Question 52

At what frequency does an object with a temperature of 1000 K radiate the most power?

A)1.0 × 10¹⁴ Hz
B)8.0 × 10¹⁴ Hz
C)2.3 × 10¹² Hz
D)6.7 × 10¹³ Hz
E)4.1 × 10¹¹ Hz

Question 53

In hydrogen any transition ending in the ground state emits a photon that

A)may be in the ultraviolet.
B)is in neither the ultraviolet nor the infrared.
C)may be in the infrared.
D)is in the infrared.
E)is in the ultraviolet.

Question 54

The Balmer series in hydrogen

A)includes the Lyman series.
B)includes both the Paschen series and the Lyman series.
C)includes the Paschen series.
D)has four lines in the ultraviolet.
E)has four lines in the visible.

Question 55

The surface temperature of the star is 6000 K. What is the wavelength associated with the light emitted by this star?

A)483 nm
B)907 nm
C)311 nm
D)492 nm
E)502 nm

Question 56

What is the surface temperature of a star, given that its radiation peak occurs at a frequency of 1.86 × 10¹⁵ Hz?

A)17,000 K
B)14,500 K
C)19,000 K
D)20,400 K
E)18,000 K

Question 57

Which of the following microscopes is capable of "photographing" individual atoms?

A)light microscope
B)scanning tunneling microscope
C)scanning electron microscope
D)transmission electron microscope
E)transmission scanning microscope

Question 58

The part of an electron microscope that plays the same role as the lenses do in an optical microscope is

A)the vacuum chamber.
B)the coils.
C)the cathode.
D)the anode.
E)the deflector plates.

Question 59

A gamma ray has an energy of 1 MeV.
(a) What is the frequency associated with this photon?
(b) What is the wavelength associated with this photon?

Question 60

A certain photon after being scattered from a free electron at rest moves at an angle of 120° with respect to the incident direction. The wavelength of the incident photon is 0.651 nm.
(a.) What is the wavelength of the scattered photon?
(b.) What is the energy of the scattered photon?

Question 61

A light-emitting diode emits one microwatt of 640 nm photons. How many photons are emitted each second?

A)2.5 × 10²⁰
B)9.7 × 10²⁰
C)2.0 × 10³¹
D)3.0 × 10²¹
E)3.2 × 10¹²

Question 62

In a particular case of Compton scattering, a photon collides with a free electron and scatters backwards. The wavelength after the collision is exactly double the wavelength before the collision. What is the wavelength of the incident photon?

A)3.6 × 10^-12 m
B)4.8 × 10^-12 m
C)2.4 × 10^-12 m
D)1.2 × 10^-12 m
E)6.0 × 10^-12 m

Question 63

What is the momentum of a photon of light that has a frequency of 2.8 × 10¹⁴ Hz?

A)1.5 × 10^-28 kg∙m/s
B)2.1 × 10^-28 kg∙m/s
C)4.4 × 10^-28 kg∙m/s
D)6.3 × 10^-28 kg∙m/s
E)6.2 × 10^-28 kg∙m/s

Question 64

What is the number of photons per second given off by a light bulb with a power of 100 Watts operating at an efficiency of 4.80%? Assume the wavelength of light to be 600 nm.

A)6.34 × 10¹⁸ photons/s
B)5.42 × 10¹⁸ photons/s
C)3.11 × 10¹⁸ photons/s
D)25.3 × 10¹⁸ photons/s
E)14.5 × 10¹⁸ photons/s

Question 65

A beam of white light of a certain frequency is incident on a metal surface. If the work function of this surface is 2.20 eV, what frequency of light would give a maximum kinetic energy of 0.25 eV to the photoelectrons ejected from this surface?

A)2.05 × 10¹⁴ Hz
B)1.02 × 10¹⁴ Hz
C)2.50 × 10¹⁴ Hz
D)3.53 × 10¹⁴ Hz
E)5.92 × 10¹⁴ Hz

Question 66

A photon of wavelength 1.50 × 10^-10 m is scattered at an angle of 90° in the Compton effect. The wavelength of the scattered photon is

A)1.52 × 10^-10 m
B)1.49 × 10^-10 m
C)1.48 × 10^-10 m
D)1.51 × 10^-10 m
E)1.50 × 10^-10 m

Question 67

A surface has a work function 1.70 eV and has light of wavelength 400 nm shone on it. What is the maximum speed of the photoelectrons emitted?

A)1.0 × 10⁶ m/s
B)1.3 × 10⁶ m/s
C)7.0 × 10⁵ m/s
D)7.7 × 10⁵ m/s
E)3.5 × 10⁶ m/s

Question 68

What is the longest wavelength of light that can cause photoelectron emission from a metal that has a work function of 2.20 eV?

A)417 nm
B)257 nm
C)344 nm
D)564 nm
E)610 nm

Question 69

What is the cutoff frequency for a metal surface that has a work function of 5.42 eV?

A)1.31 × 10¹⁵ Hz
B)2.01 × 10¹⁵ Hz
C)3.01 × 10¹⁵ Hz
D)5.02 × 10¹⁵ Hz
E)6.04 × 10¹⁵ Hz

Question 70

A surface has a work function 1.70 eV and has light of wavelength 400 nm shone on it. What is the kinetic energy of the photoelectrons emitted?

A)4.52 eV
B)3.11 eV
C)1.41 eV
D)2.82 eV
E)1.70 eV

Question 71

A 60-W bulb is operating at an efficiency of 6.20%. What is the number of photons per second given off by the bulb assuming the wavelength of light to be 580 nm?

A)5.42 × 10¹⁸ photons/s
B)10.8 × 10¹⁸ photons/s
C)16.2 × 10¹⁸ photons/s
D)21.7 × 10¹⁸ photons/s
E)25.3 × 10¹⁸ photons/s

Question 72

A photon has an energy of 6.60 eV. To what wavelength does this energy correspond?

A)100 nm
B)118 nm
C)151 nm
D)173 nm
E)189 nm

Question 73

A beam of light with a frequency range of 3.01 × 10¹⁴ Hz - 6.10 × 10¹⁴ Hz is incident on a metal surface. If the work function of the metal surface is 2.20 eV, what is the range of frequencies in this beam of light that will be responsible for ejecting electrons from this metal surface?

A)1.12 × 10¹⁴ Hz - 5.31 × 10¹⁴ Hz
B)1.12 × 10¹⁴ Hz - 3.10 × 10¹⁴ Hz
C)3.01 × 10¹⁴ Hz - 6.10 × 10¹⁴ Hz
D)5.31 × 10¹⁴ Hz - 6.10 × 10¹⁴ Hz
E)None

Question 74

A beam of light with a frequency range of 3.01 × 10¹⁴ Hz - 6.10 × 10¹⁴ Hz is incident on a metal surface. If the work function of the metal surface is 2.20 eV, what is the maximum kinetic energy of photoelectrons ejected from this surface?

A)0.32 eV
B)0.21 eV
C)0.42 eV
D)0.16 eV
E)0.48 eV

Question 75

Electrons are emitted from a surface when light of wavelength 500 nm is shone on the surface but electrons are not emitted for longer wavelengths of light. The work function of the surface is

A)5.0 eV.
B)0.60 eV.
C)2.5 eV.
D)4.0 eV.
E)0.40 eV.

Question 76

Light with a frequency of 8.70 × 10¹⁴ Hz is incident on a metal that has a work function of 2.8 eV. What is the maximum kinetic energy that a photoelectron ejected in this process can have?

A)8.71 × 10^-19 J
B)3.11 × 10^-19 J
C)1.28 × 10^-19 J
D)2.41 × 10^-19 J
E)4.52 × 10^-19 J

Question 77

Light with a wavelength of 310 nm is incident on a metal that has a work function of 3.8 eV. What is the maximum kinetic energy that a photoelectron ejected in this process can have?

A)0.62 × 10^-19 J
B)0.21 × 10^-19 J
C)0.36 × 10^-19 J
D)0.48 × 10^-19 J
E)0.33 × 10^-19 J

Question 78

The work function of a certain metal is 1.90 eV. What is the longest wavelength of light that can cause photoelectron emission from this metal?

A)231 nm
B)14.0 nm
C)62.4 nm
D)344 nm
E)653 nm

Question 79

What is the momentum of a photon of light that has a wavelength of 480 nm?

A)1.1 × 10^-27 kg∙m/s
B)2.2 × 10^-27 kg∙m/s
C)1.8 × 10^-27 kg∙m/s
D)1.4 × 10^-27 kg∙m/s
E)2.0 × 10^-27 kg∙m/s

Question 80

If a surface has a work function of 1.5 eV and photons of energy 2.7 eV are shone on the surface, what is a possible kinetic energy of the electrons emitted from the surface?

A)3.0 eV
B)2.0 eV
C)4.0 eV
D)1.0 eV
E)No electrons are emitted.