Deck 15: Quantum Theory

Question 1

In the relationship E = hf for a photon emitted from an atom, the symbol E is used to represent the energy

A) of the emitted photon.
B) difference between atomic energy states producing the photon.
C) both of these
D) neither of these

Answer 1

both of these

Question 2

Atoms of neon in a glass tube can be excited

A) over and over again.
B) once per atom.

Answer 2

over and over again.

Question 3

The uncertainty principle applies not only to momentum and position, but also to energy and time. This statement is

Answer 3

True

Question 4

An atom that emits a certain frequency of light is

A) an absorber of the same frequency.
B) not likely to absorb that same frequency.

Question 5

The quantum-mechanical probability cloud for the electron in the hydrogen atom has an average radius

A) that agrees with the orbital radius of Bohr.
B) quite different from the radius predicted by Bohr.

Question 6

A uranium atom is 238 times as massive as a hydrogen atom. The diameter of a uranium atom is the diameter of a hydrogen atom times about

A) 3.
B) 30.
C) 100.
D) 238.
E) 10.

Question 7

The energy of a photon is related to

A) the energy level difference though which it falls.
B) its frequency.
C) the energy given to the atom that emits it.
D) all of these
E) none of these

Question 8

A hypothetical atom has four distinct energy states. Assuming all transitions are possible, how many spectral lines can this atom produce?

A) 6
B) 7
C) 5
D) 8
E) more than 8

Question 9

Heavy atoms are not appreciably larger in size than light atoms because the nuclei of heavy atoms have more

A) nucleons.
B) mass.
C) electric charge.
D) all of these
E) none of these

Question 10

Spectral lines take the shape of vertical lines because

A) the energy levels in the atom are parallel to one another.
B) the light is vertically polarized.
C) they are simply images of a vertical slit.
D) all of these
E) none of these

Question 11

The main visible difference between phosphorescent and fluorescent materials is

A) the greenish color of phosphorescence.
B) an afterglow.
C) a difference in brightness.

Question 12

In the Bohr model of hydrogen, discrete radii and energy states result when an electron circles the atom in an integral number of

A) diffraction patterns.
B) de Broglie wavelengths.
C) wave frequencies.
D) none of these

Question 13

When a clean surface of potassium metal is exposed to blue light, electrons are emitted. If the intensity of the blue light is increased, which of the following will also increase?

A) the number of electrons ejected per second
B) the threshold frequency of the ejected electrons
C) the maximum kinetic energy of the ejected electrons
D) the time lag between the absorption of blue light and the start of emission of the electrons
E) none of these

Question 14

Fluorescent minerals on display in museums are illuminated with

A) ultraviolet light.
B) infrared light.
C) often either or both
D) none of these

Question 15

Two photons are emitted as an electron de-excites from the third quantum level to the second, and then to the ground state. The sum of the frequencies of the two photons equals the frequency of the single photon that would be emitted if the de-excitation were from the third to the ground state directly. This is according to

A) the physicist W. Ritz.
B) energy conservation.
C) both of these
D) neither of these

Question 16

The photoelectric effect best demonstrates the

A) wave nature of light.
B) particle nature of light.
C) both of these
D) none of these

Question 17

A certain object emits infrared waves. If it were to emit light waves instead, its temperature would have to be

A) higher.
B) lower.
C) the same, temperature doesn't make any difference.

Question 18

Light behaves primarily as a wave when it

A) interacts with matter.
B) travels from one place to another.

Question 19

Compared to the average diameter of a hydrogen atom, the average diameter of a helium atom is

A) smaller.
B) larger.
C) about the same.

Question 20

Discrete spectral lines occur when excitation takes place in a

A) liquid.
B) solid.
C) gas.
D) superconductor.
E) all of these

Question 21

In the double-slit experiment with electrons, the electrons arrive at the screen in a

A) particle-like way with a pattern that is wave-like.
B) particle-like way with a pattern that is particle-like.
C) wave-like way with a pattern that is particle-like.
D) wave-like way with a pattern that is wave-like.

Question 22

An excited atom decays to its ground state and emits a photon of green light. If instead the atom decays to an intermediate state, then the light emitted could be

A) violet.
B) red.
C) blue.
D) any of these
E) none of these

Question 23

The correspondence principle applies to

A) theories of submicroscopic phenomena.
B) theories of macroscopic phenomena.
C) all good theories.

Question 24

In the process of fluorescence, the input is high-frequency light and the output is

A) equally high-frequency light.
B) lower-frequency light.
C) higher-frequency light.

Question 25

A quantum of light is called a

A) notron.
B) electron.
C) neutron.
D) proton.
E) none of these

Question 26

Which has more energy per photon?

A) red light
B) blue light
C) Both have the same energy.

Question 27

Which of the following is not quantized?

A) energy
B) electric charge
C) radiation
D) number of people in a room
E) All are quantized.

Question 28

Light frequency from an incandescent lamp depends on the

A) transparency of glass.
B) voltage applied to the lamp.
C) electrical resistance of the lamp.
D) amount of electrical energy transformed.
E) rate of atomic and molecular vibrations.

Question 29

An excited atom is an atom

A) with more protons than electrons.
B) that has one or more displaced electrons.
C) that has excess vibration.
D) that is frantic.

Question 30

Two beams of light, a red beam and a blue beam, have the same energy. The beam with the greater number of photons is the

A) blue beam.
B) red beam.
C) both the same

Question 31

In the photoelectric effect, the brighter the illuminating light on a photosensitive surface, the greater the

A) number of ejected electrons.
B) velocity of ejected electrons.
C) both of these
D) neither of these

Question 32

The variety of colors seen in a burning log come from the variety of

A) absorbing gases between the log and the viewer.
B) chemicals in the log.
C) electron transitions in various atoms.
D) temperatures.
E) multi-layered incandescent surfaces.

Question 33

Atoms can be excited by

A) photon impact.
B) electron impact.
C) thermal agitation.
D) all of these
E) none of these

Question 34

A photosensitive surface is illuminated with both blue and violet light. The light that will cause the most electrons to be ejected is the

A) violet light.
B) blue light.
C) Both eject the same number.
D) not enough information given

Question 35

Compared to the energy of a photon of red light, the energy of a photon of blue light is

A) less.
B) more.
C) the same.

Question 36

In the equation E = hf, the f stands for

A) frequency characteristic of quantum phenomena.
B) the smaller wavelengths of visible light.
C) wave frequency as defined for sound, radio, and light waves.
D) none of these

Question 37

Helium was first discovered in the

A) upper atmosphere.
B) island of Helios, in Greece.
C) byproducts of nuclear fusion.
D) sun.
E) laboratory.

Question 38

Compared to the energy put into a laser, the energy of the laser beam is

A) the same.
B) more.
C) less.

Question 39

Astronomers can tell whether a star is approaching or receding from earth by

A) the Doppler effect.
B) its temperature.
C) its change in temperature.
D) its absorption spectra.
E) all of these

Question 40

A new theory conforms to the correspondence principle when it

A) corresponds to all theories in nature.
B) accounts for verified results of the old theory.
C) ties two or more theories together.
D) updates the essence of the old theory.
E) none of these

Question 41

Quantum uncertainties are most predominant for simultaneously measuring the speed and location of

A) a spitball.
B) a baseball.
C) an electron.

Question 42

An atom that absorbs a photon of a certain energy can then emit

A) only a photon of the same or higher energy.
B) a photon of any energy.
C) only a photon of that energy.
D) only a photon of the same or lower energy.

Question 43

If atoms were smaller, Planck's constant would be

A) larger.
B) smaller.
C) no different in physical size.

Question 44

Orbital electrons do not spiral into the nucleus because of

A) electromagnetic forces.
B) angular momentum conservation.
C) the wave nature of the electron.
D) the large nuclear size compared to the electron's size.
E) none of these

Question 45

Which has less energy per photon?

A) blue light
B) red light
C) Both have the same energy.

Question 46

The ratio of a photon's energy to its frequency is

A) its speed.
B) its wavelength.
C) Planck's constant.
D) its amplitude.
E) none of these

Question 47

An excited hydrogen atom is capable of emitting radiation of

A) a single frequency.
B) 3 frequencies.
C) many more than 3 frequencies.

Question 48

The highest frequency light of those below is

A) red.
B) blue.
C) green.
D) violet.
E) all the same

Question 49

A lump of energy associated with light is called a

A) photon.
B) quantum.
C) both of these
D) neither of these

Question 50

Isolated bells ring clear, while bells crammed in a box have a muffled ring. If the sound of isolated bells is analogous to light from a gas discharge tube, then sound from the box crammed with bells
Is analogous to light from

A) a fluorescent lamp.
B) an incandescent lamp.
C) a laser.
D) a phosphorescent source.
E) none of these

Question 51

We now consider the Bohr model of the atom to be

A) totally useless - of historical interest only.
B) defective and oversimplified, but still useful.
C) an accurate picture of a hydrogen atom.

Question 52

The greater proportion of energy immediately converted to heat rather than light occurs in

A) a fluorescent lamp.
B) an incandescent lamp.
C) both the same

Question 53

The white light emitted by a fluorescent lamp is provided by the

A) filtering effect of the glass tubing.
B) phosphors on the inner surface of the lamp.
C) high temperature of the glowing gas.
D) mercury vapor in the lamp.

Question 54

Compared to the wavelengths of visible light, the wavelengths of matter waves are relatively

A) large.
B) small.

Question 55

The main reason electrons occupy discrete orbits in an atom is because

A) electric forces act over quantized distances.
B) energy levels are quantized.
C) electrons are basically discrete particles.
D) the circumference of each orbit is an integral multiple of electron wavelengths.
E) none of these

Question 56

The fact that iron absorption lines occur in the solar spectrum directly indicates that there is iron in the solar

A) interior.
B) atmosphere.
C) surface.

Question 57

According to quantum physics, looking at a star through a telescope

A) affects the processes occurring in the star.
B) has no effect on the processes occurring in the star.

Question 58

The dark lines in the sun's spectrum represent light that is

A) emitted by the sun.
B) absorbed by the sun's atmosphere.
C) not emitted by the sun.

Question 59

In the photoelectric effect, the greater the frequency of the illuminating light, the greater the

A) number of ejected electrons.
B) maximum velocity of ejected electrons.
C) both of these
D) neither of these

Question 60

In the process of fluorescence, part of the input energy immediately

A) is emitted as higher-frequency light and the rest lower- frequency light.
B) becomes internal energy and the rest lower-frequency light.
C) cascades to excite other atoms in the material.
D) excites electrons to metastable states.
E) none of these

Question 61

The ratio of the energy of a photon to its frequency is

A) pi.
B) the photon's speed.
C) the photon's wavelength.
D) Planck's constant.
E) not known.

Question 62

Which color of light carries the most energy per photon?

A) red
B) violet
C) blue
D) green
E) all the same

Question 63

If light in a spectroscope were passed through a star-shaped opening instead of a thin slit, spectral lines would appear as

A) blobs of no definite shape.
B) stars.
C) lines, but with poorer resolution.

Question 64

Light from a laser is

A) in phase.
B) monochromatic.
C) coherent.
D) all of these
E) none of these

Question 65

The Bohr model of the atom is akin to a

A) miniature solar system.
B) central heavy ball with lighter balls connected by springs.
C) blob of plum pudding, where raisins represent atomic nuclei.
D) all of these

Question 66

Which experiment best demonstrates the particle-like nature of light?

A) double-slit experiment
B) photoelectric effect
C) neither

Question 67

To say that energy levels in an atom are discrete is to say the energy levels are well defined and

A) separated from one another by the same energy increments.
B) private.
C) separate from one another.
D) continuous.

Question 68

A throbbing pulse of electromagnetic radiation is called a

A) photon.
B) proton.
C) lightron.
D) notron.
E) sparktron.

Question 69

Physics pioneers Balmer, Rydberg, and Ritz discovered in atomic spectra

A) that all atoms are essentially the same size.
B) that electrons behave as standing waves.
C) a randomness that opened the door to the nature of probabilities in atomic reality.
D) mathematical order.
E) that electrons occupy well-defined shells about the atomic nucleus.

Question 70

Light is emitted when an electron

A) makes a transition to a lower energy level.
B) is boosted to a higher energy level.
C) neither of these

Question 71

If light in a spectroscope passed through round holes instead of slits, spectral lines would appear

A) round.
B) dimmer.
C) as thicker lines.

Question 72

Light behaves primarily as a particle when it

A) travels from one place to another.
B) interacts with matter.

Question 73

Ultraviolet light is

A) present everywhere.
B) more energetic than X-rays.
C) produced by crossed Polaroids.
D) electromagnetic energy.
E) none of these

Question 74

As a solid is gradually heated, the first color to glow is

A) blue.
B) white.
C) red.
D) yellow.

Question 75

According to the uncertainty principle, the more we know about a particle's momentum, the less we know about its

A) speed.
B) location.
C) mass
D) kinetic energy.
E) none of these

Question 76

If the energy levels in the neon atom were not discrete, neon signs would glow

A) white.
B) blue.
C) red.

Question 77

To study the energy of photoelectrons we measure

A) the time they take to go a given distance.
B) their temperature.
C) the distance they travel in a given time.
D) the potential difference required to stop them.

Question 78

Quantization of electron energy states in an atom is better understood in terms of the electron's

A) wave nature.
B) particle nature.
C) neither of these

Question 79

Electrons with the greater potential energies with respect to the atomic nucleus are

A) outer electrons.
B) inner electrons.
C) both the same, actually

Question 80

Which of the following continually emits electromagnetic radiation?

A) insects
B) red-hot coals
C) radio antennas
D) all of these
E) none of these