1. The Atom and the Quantum
Chapter 32
The Atom and the Quantum

2. When Rutherford directed a beam of alpha particles into gold foil, most of the alpha particles
were stopped.
bounced back.
continued straight through.
underwent small deflections.
Answer: C

3. When Rutherford directed a beam of alpha particles into gold foil, most of the alpha particles
were stopped.
bounced back.
continued straight through.
underwent small deflections.
Answer: C
Explanations: Some particles were deflected, but most went through as if the foil were empty space. Only a few bounced back.

4. Which of these is largest in size?
An electron
An alpha particle
The nucleus of a gold atom
All about the same.
Answer: C

5. Which of these is largest in size?
An electron
An alpha particle
The nucleus of a gold atom
All about the same.
Answer: C
Explanation: An electron can reside in any nucleus as a beta particle ready to be released, and an alpha particle is the nucleus of a helium atom, much smaller than a gold nucleus.

6. An electron in a cathode ray is
distinct from an electron that makes up lightning.
related but different from electrons whose acceleration produces light.
like any other electron.
None of the above.
Answer: C

7. An electron in a cathode ray is
distinct from an electron that makes up lightning.
related but different from electrons whose acceleration produces light.
like any other electron.
None of the above.
Answer: C
Comment: A premise of physics is that all electrons are identical.

8. Electron beams can undergo
diffraction.
interference.
deflection.
All of the above.
Answer: D

9. Electron beams can undergo
diffraction.
interference.
deflection.
All of the above.
Answer: D

10. The electric charge in a beam of electrons is
continuous.
quantized.
the same as the charge on a quark.
None of these.
Answer: B

11. The electric charge in a beam of electrons is
continuous.
quantized.
the same as the charge on a quark.
None of these.
Answer: B
Comment: Whether or not you know that the charge of a quark is a fraction of the charge of an electron, what you should know is that electric charge is quantized.

12. A beam of electrons has particle properties. wave properties.
Both of these.
None of these.
Answer: C

13. A beam of electrons has particle properties. wave properties.
Both of these.
None of these.
Answer: C

14. A model of an atom is useful when it
shows how an atom appears.
magnifies what the eye can’t see.
helps to visualize processes that are difficult to visualize.
verifies truth.
Answer: C

15. A model of an atom is useful when it
shows how an atom appears.
magnifies what the eye can’t see.
helps to visualize processes that are difficult to visualize.
verifies truth.
Answer: C

16. The planetary model of the atom, with electrons buzzing around the nucleus like planets orbiting the Sun, is
today’s dominant model of the atom.
is still helpful in some cases, but has been replaced by other models.
complete nonsense.
useful in primitive societies only.
Answer: B

17. The planetary model of the atom, with electrons buzzing around the nucleus like planets orbiting the Sun, is
today’s dominant model of the atom.
is still helpful in some cases, but has been replaced by other models.
complete nonsense.
useful in primitive societies only.
Answer: B

18. The frequencies of light are nicely measured using
an electron microscope.
a spectoscope.
interference techniques.
standing-wave analysis.
Answer: B

19. The frequencies of light are nicely measured using
an electron microscope.
a spectoscope.
interference techniques.
standing-wave analysis.
Answer: B

20. The addition of a pair of light frequencies emitted by an atom often equals a
higher frequency of light emitted by the same atom.
lower frequency of light emitted by the same atom.
composite of all emitted frequencies.
None of the above.
Answer: A

21. The addition of a pair of light frequencies emitted by an atom often equals a
higher frequency of light emitted by the same atom.
lower frequency of light emitted by the same atom.
composite of all emitted frequencies.
None of the above.
Answer: A
Explanation: This follows from two energy transitions in an atom summing to equal a third energy transition. See Figure

22. Orbital electrons don’t spiral into the atomic nucleus because of
angular momentum conservation.
energy conservation.
the wave nature of electrons.
All of the above.
Answer: C

23. Orbital electrons don’t spiral into the atomic nucleus because of
angular momentum conservation.
energy conservation.
the wave nature of electrons.
All of the above.
Answer: C
Comment: The wave nature prevents spiraling, not the conservation principles stated.

24. The radii of electrons about the atomic nucleus are nicely understood by thinking of the electrons as
standing waves.
discrete particles.
resonating vibrations.
reflections.
Answer: A

25. The radii of electrons about the atomic nucleus are nicely understood by thinking of the electrons as
standing waves.
discrete particles.
resonating vibrations.
reflections.
Answer: A

26. The greater the number of protons in a nucleus, the
larger the outermost electron orbits.
tighter the electron orbits.
looser inner orbits become.
None of these.
Answer: B

27. The greater the number of protons in a nucleus, the
larger the outermost electron orbits.
tighter the electron orbits.
looser inner orbits become.
None of these.
Answer: B

28. A current model of the atom sees electrons about the atomic nucleus
as if they were tiny planets in orbit.
in shells.
pulled by springlike forces.
as spectral lines.
Answer: B

29. A current model of the atom sees electrons about the atomic nucleus
as if they were tiny planets in orbit.
in shells.
pulled by springlike forces.
as spectral lines.
Answer: B

30. The thing that waves in the Schrödinger wave equation
is energy itself.
is a wave function,  .
is density amplitudes.
is electron clouds.
Answer: B

31. The thing that waves in the Schrödinger wave equation
is energy itself.
is a wave function,  .
is density amplitudes.
is electron clouds.
Answer: B

32. According to Schrödinger, the location of an electron in an atom can be
at an average distance from the nucleus described by Bohr.
somewhere between the nucleus and the outer edge of the electron cloud.
inside the nucleus.
All of these.
Answer: D

33. According to Schrödinger, the location of an electron in an atom can be
at an average distance from the nucleus described by Bohr.
somewhere between the nucleus and the outer edge of the electron cloud.
inside the nucleus.
All of these.
Answer: D

34. Determining the location of a specific electron in an atom is
not doable without proper tools.
probabilistic only.
something that Schrödinger and his team of investigators were the first to do.
None of the above.
Answer: B

35. Determining the location of a specific electron in an atom is
not doable without proper tools.
probabilistic only.
something that Schrödinger and his team of investigators were the first to do.
None of the above.
Answer: B

36. Subatomic interactions described by quantum mechanics are governed by
the same laws of classical physics.
laws of certainty.
laws of probability.
exact measurements.
Answer: C

37. Subatomic interactions described by quantum mechanics are governed by
the same laws of classical physics.
laws of certainty.
laws of probability.
exact measurements.
Answer: C

38. According to the correspondence principle,
new theory must agree with old theory where they overlap.
the Schrödinger atom is a special case of the Bohr model of the atom.
de Broglie’s matter waves are much the same in nature as sound waves.
All of the above.
Answer: A

39. According to the correspondence principle,
new theory must agree with old theory where they overlap.
the Schrödinger atom is a special case of the Bohr model of the atom.
de Broglie’s matter waves are much the same in nature as sound waves.
All of the above.
Answer: A
Comment: The statements about the Schrödinger atom and de Broglie’s matter waves are false!

40. The correspondence principle applies to
submicroscopic phenomena.
macroscopic phenomena.
gravitation and quantum theories.
all good theories.
Answer: D

41. The correspondence principle applies to
submicroscopic phenomena.
macroscopic phenomena.
gravitation and quantum theories.
all good theories.
Answer: D