Deck 9: The Atom

Question 1

Photons have

A)no charge.
B)charges smaller than $\pm$ e, like quarks.
C)charges of $\pm$ e.
D)charges whose magnitudes depends on their speeds.

Answer 1

no charge.

Question 2

In order to increase the rate at which photoelectrons are emitted by a surface on which light is directed, it is necessary to increase the

A)frequency of the light.
B)wavelength of the light.
C)intensity of the light.
D)speed of the light.

Answer 2

intensity of the light.

Question 3

According to the uncertainty principle, it is impossible to precisely determine

A)only the position of a particle.
B)only the momentum of a particle.
C)either the position or the momentum of a particle.
D)both the position and the momentum of a particle.

Answer 3

both the position and the momentum of a particle.

Question 4

The narrower the wave packet of a particle is, the

A)longer its wavelength.
B)more precisely its position can be established.
C)more precisely its momentum can be established.
D)more precisely its energy can be established.

Question 5

A proton and an electron have the same de Broglie wavelength.

A)The electron has the higher speed.
B)The proton has the higher speed.
C)They have the same speed.
D)Any of the choices is true, depending on the wavelength.

Question 6

A moving body is described by its wave function at a certain time and place.The value of is proportional to the body's

A)electric field.
B)speed.
C)energy.
D)probability of being found.

Question 7

X-rays are

A)electromagnetic waves of very short wavelength.
B)electromagnetic waves of very long wavelength.
C)matter waves of very short wavelength.
D)matter waves of very long wavelength.

Question 8

If Planck's constant were larger than it is,

A)moving bodies would have longer wavelengths.
B)moving bodies would have smaller energies.
C)moving bodies would have higher speeds.
D)the uncertainty principle would be more significant.

Question 9

The idea that light has both wave and particle properties is accepted because

A)theory and experiment agree.
B)it is in accord with common sense.
C)it was revealed to Einstein in a dream.
D)photons have actually been seen.

Question 10

An electron and a gamma ray have the same wavelength.

A)The electron has less energy than the photon energy of the gamma ray.
B)The electron has the same energy as the photon energy of the gamma ray.
C)The electron has more energy than the photon energy of the gamma ray.
D)Any of these choices could be correct, depending on the wavelength.

Question 11

The uncertainty principle is a fundamental part of

A)Newtonian mechanics.
B)quantum mechanics.
C)the quantum theory of light.
D)the Bohr theory of the hydrogen atom.

Question 12

Matter waves are

A)associated with all particles.
B)never associated with stationary particles.
C)never associated with charged particles.
D)never associated with uncharged particles.

Question 13

When light is directed at a metal surface, the emitted electrons

A)are called photons.
B)have random energies.
C)have energies that depend upon the intensity of the light.
D)have energies that depend upon the frequency of the light.

Question 14

Which one or more of the following can be explained by the quantum theory of light?

A)interference
B)diffraction
C)the photoelectric effect
D)matter waves

Question 15

The wave character of a moving golf ball is not observed because

A)the ball is uncharged.
B)the matter waves are moving too fast.
C)the frequency of the matter waves is too low.
D)the wavelength of the matter waves is too short.

Question 16

An increase in the voltage applied to an X-ray tube causes an increase in the X-rays'

A)wavelength.
B)speed.
C)energy.
D)number.

Question 17

The photoelectric effect occurs only when the incident light has more than a certain minimum

A)frequency.
B)wavelength.
C)speed.
D)charge.

Question 18

The speed of the wave packet that corresponds to a moving particle is

A)less than the speed of light.
B)equal to the speed of light.
C)greater than the speed of light.
D)Any of these choices could be correct, depending on the frequency.

Question 19

Which one or more of the following can be explained by the electromagnetic theory of light?

A)interference
B)diffraction
C)the photoelectric effect
D)matter waves
E)Both A and B

Question 20

The speed of a photon

A)is less than the speed of light.
B)is equal to the speed of light.
C)is greater than the speed of light.
D)Any of these choices could be correct, depending on its frequency.

Question 21

Classical physics cannot account for why

A)atoms can contain electrons.
B)atomic electrons are in motion.
C)atoms can emit electromagnetic waves.
D)atoms can be stable.

Question 22

Which of the following electron jumps in a hydrogen atom emits the photon of lowest frequency?

A)n = 1 to n = 2
B)n = 2 to n = 1
C)n = 2 to n = 3
D)n = 3 to n = 2

Question 23

The bright-line spectrum produced by the excited atoms of an element contains wavelengths that are

A)the same for all elements.
B)characteristic of the particular element.
C)evenly distributed throughout the entire visible spectrum.
D)different from the wavelengths in its dark-line spectrum.

Question 24

The fact that no two electrons in an atom can have the same set of quantum numbers is known as the

A)Bohr principle.
B)de Broglie principle.
C)exclusion principle.
D)uncertainty principle.

Question 25

An atom in an excited state usually emits a photon and falls to a state of lower energy m about

A)10^-8 s.
B)1 s.
C)10 s.
D)1 min.

Question 26

The quantum number n of the lowest energy state of a hydrogen atom

A)is 0.
B)is 1.
C)depends on the orbit size.
D)depends on the electron speed.

Question 27

When a hydrogen atom is in its lowest energy level,

A)the de Broglie wavelength of its electron equals its orbit diameter.
B)the de Broglie wavelength of its electron equals its orbit circumference.
C)its electron has left the atom.
D)its electron is at rest.

Question 28

Which one or more of the following events can raise an atom from its ground state to an excited state?

A)spontaneous emission of a photon
B)induced emission of a photon
C)absorption of a photon
D)a collision with another atom
E)Both C and D

Question 29

A beam of light whose waves are all in step with one another is said to be

A)coherent.
B)incoherent.
C)quantized.
D)diffracted.

Question 30

Which of the following electron jumps in a hydrogen atom absorbs the photon of highest frequency?

A)n = 1 to n = 2
B)n = 2 to n = 1
C)n = 2 to n = 3
D)n = 3 to n = 2

Question 31

A photon is emitted by an atom when one of the atom's electrons

A)leaves the atom.
B)collides with another of its electrons.
C)shifts to a lower energy level.
D)shifts to a higher energy level.

Question 32

In an emission spectral series, the

A)lines are evenly spaced.
B)excited electrons all started from the same energy level.
C)excited electrons all return to the same energy level.
D)excited electrons leave the atoms.

Question 33

The energy difference between adjacent energy levels in an atom

A)is the same for all quantum numbers.
B)is smaller for small quantum numbers.
C)is larger for large quantum numbers.
D)shows no regularity.

Question 34

A neon sign does not produce

A)a line spectrum.
B)an emission spectrum.
C)an absorption spectrum.
D)photons.

Question 35

Most stars are hot objects surrounded by cooler atmospheres.The spectrum of such a star is a

A)continuous band of light.
B)band of light crossed by brighter lines.
C)band of light crossed by dark lines.
D)series of bright lines.

Question 36

The light waves from a laser

A)have different wavelengths.
B)have different speeds.
C)are in step with one another.
D)spread out to form a wide beam.

Question 37

Electrons

A)have no magnetic properties.
B)have the same magnetic behavior as particles of iron.
C)behave like tiny bar magnets of different strengths.
D)behave like tiny bar magnets of the same strength.

Question 38

The number of quantum numbers needed to determine the size and shape of the probability cloud of an atomic electron is

A)1.
B)2.
C)3.
D)4.

Question 39

The number of values the spin magnetic quantum number m_s of an atomic electron can have is

A)1.
B)2.
C)always equal to n, the principal quantum number.
D)always equal to 2n.

Question 40

Which of the following electron jumps in a hydrogen atom emits the photon of highest frequency?

A)n = 1 to n = 2
B)n = 2 to n = 1
C)n = 2 to n = 3
D)n = 3 to n = 2

Question 41

Planck's constant is 6.6 * 10^-34 J·s and the proton mass is 1.7 * 10^-27 kg.The speed of a proton whose de Broglie wavelength is 4.0 * 10⁷ m is

A)7.8 * 10^-20 m/s.
B)9.9 * 10² m/s.
C)1.9 * 10⁶ m/s.
D)3.9 * 10⁶ m/s.

Question 42

Planck's constant is h = 6.6 * 10^-34 J·s.The energy of a photon of light whose frequency is 3 * 10¹⁴ Hz is

A)2.2 * 10^-48 J.
B)1.98 * 10^-47 J.
C)1.98 * 10^-19 J.
D)4.5 * 10¹⁹ J.

Question 43

Each probability cloud in an atom can be occupied by

A)only one electron.
B)two electrons with spins in the same direction.
C)two electrons with spins in opposite directions.
D)any number of electrons.

Question 44

A lamp emits light of frequency 5 * 10¹⁵ Hz at a power of 25 W and Planck's constant is 6.6 * 10^-34 J·s.The number of photons given off per second is

A)1.3 * 10^-19.
B)8.3 * 10^-17.
C)7.6 * 10¹⁸.
D)1.9 * 10⁵⁰.

Question 45

Planck's constant is 6.6 * 10^-34 J·s and the electron mass is 9.1 * 10^-31 kg.The de Broglie wavelength of an electron whose speed is 2.0 * 10⁷ m/s is

A)2.8 * 10^-10 m.
B)3.6 * 10^-10 m.
C)3.6 * 10^-11 m.
D)2.8 * 10¹⁰ m.

Question 46

An X-ray photon has an energy of 3.3 * 10¹⁵ J and Planck's constant is 6.6 * 10^-34 J·s.The frequency that corresponds to this energy is

A)3.3 * 10^-50 Hz.
B)3 * 10^-19 Hz.
C)3.3 * 10¹⁸ Hz.
D)3.3 * 10²⁰ Hz.