College Physics: A Strategic Approach, 3e (Knight)
Chapter 29 Atoms and Molecules
29.1 Conceptual Questions
1) To which of the following values of n does the longest wavelength in the Balmer series
correspond?
A) 3
B) 5
C) 1
D) 7
E) ∞ (very large)
2) To which of the following values of n does the shortest wavelength in the Balmer series
correspond?
A) 3
B) 5
C) 7
D) 1
E) ∞ (very large)
3) The Balmer series is formed by electron transitions in hydrogen that
A) end on the n = 1 shell.
B) begin on the n = 1 shell.
C) end on the n = 2 shell.
D) begin on the n = 2 shell.
E) are between the n = 1 and n = 3 shells.
4) The Lyman series is formed by electron transitions in hydrogen that
A) end on the n = 1 shell.
B) begin on the n = 1 shell.
C) end on the n = 2 shell.
D) begin on the n = 2 shell.
E) are between the n = 1 and n = 3 shells.
5) The Paschen series is formed by electron transitions that
A) end on the n = 1 shell.
B) begin on the n = 1 shell.
C) end on the n = 2 shell.
D) begin on the n = 3 shell.
E) end on the n = 3 shell.
6) Hydrogen atoms can emit four spectral lines with visible colors from red to violet. These four
visible lines emitted by hydrogen atoms are produced by electrons
A) that start in the n = 2 level.
B) that end up in the n = 2 level.
C) that end up in the n = 3 level.
D) that end up in the ground state.
E) that start in the ground state.
7) When an electron jumps from an orbit where n = 4 to one where n = 2
A) a photon is emitted.
B) a photon is absorbed.
C) two photons are emitted.
D) two photons are absorbed.
E) None of the given answers are correct.
8) The energy difference between adjacent orbit radii in a hydrogen atom
A) increases with increasing values of n.
B) decreases with increasing values of n.
C) remains constant for all values of n.
D) varies randomly with increasing values of n.
9) The figure shows part of the energy level diagram of a certain atom. The energy spacing
between levels 1 and 2 is twice that between 2 and 3. If an electron makes a transition from level
3 to level 2, the radiation of wavelength λ is emitted. What possible radiation wavelengths might
be produced by other transitions between the three energy levels?
A) both λ/2 and λ/3
B) only λ/2
C) both 2λ and 3λ
D) only 2λ
10) The distance between adjacent orbits in a hydrogen atom
A) increases with increasing values of n.
B) decreases with increasing values of n.
C) remains constant for all values of n.
D) varies randomly with increasing values of n.
11) If a hydrogen atom originally in a state with principal quantum number n is excited to state
n‘ = 2n, then
A) its radius and binding energy will double.
B) its radius will quadruple and the binding energy will double.
C) its radius will double and the binding energy will quadruple.
D) its radius will quadruple and the binding energy will be reduced by a factor of four.
E) its radius and binding energy will quadruple.
12) Which of the following statements are true for the Bohr model of the atom? (There could be
more than one correct choice.)
A) The spacing between all the electron shells is the same.
B) The energy difference between all the electron shells is the same.
C) As we look at higher and higher electron shells, they get closer and closer together, but the
difference in energy between them gets greater and greater.
D) As we look at higher and higher electron shells, they get farther and farther apart, but the
difference in energy between them gets smaller and smaller.
E) There is no general pattern in the spacing of the shells or their energy differences.
13) A hydrogen atom is in the 6h state. What is the principal quantum number.
A) 0
B) 3
C) 5
D) 6
E) 7
14) The orbital angular momentum quantum number can take which of the following values for
any given value of the principal quantum number, n?
A) ℓ = 0, 1, 2, . . .
B) ℓ = 0, 1, 2, . . . , n
C) ℓ = 0, 1, 2, . . . , (n – 1)
D) ℓ = 1, 2, 3, 4, . . .
E) ℓ = 1, 2, 3, 4, . . ., (n + 1)
15) Which of the following values can be taken by the electron spin quantum number, ms?
A) ±1/2
B) 0
C) ±1
D) ±2
E) ±3
16) According to the quantum mechanical model of the hydrogen atom, if the orbital angular
momentum quantum number is ℓ, there will be how many permitted magnetic quantum
numbers?
A) ℓ/2
B) 2ℓ
C) 2ℓ + 1
D) 2ℓ – 1
E) 3ℓ
17) According to the quantum mechanical model of the hydrogen atom, if the principal quantum
number is n, how many different orbital angular momentum quantum numbers are permitted?
A) n/2
B) n
C) 2n
D) 3n
E) 4n
18) According to Pauli’s exclusion principle, how many electrons in an atom may have a
particular set of quantum numbers?
A) 1
B) 3
C) 2
D) 4
E) 5
19) The principal quantum number n can have any integer value ranging from
A) –∞ to +∞.
B) 0 to ∞.
C) 1 to ∞.
D) 1 to 100.
20) The orbital angular momentum quantum number ℓ can have any integer value ranging from
A) 0 to n.
B) 0 to (n-1).
C) 1 to n.
D) 1 to (n+1).
E) –n to n.
21) The magnetic quantum number m1 can have any integer value ranging from
A) –n to +n.
B) –ℓ to +ℓ.
C) 0 to n.
D) 0 to ℓ.
E) 0 to (n-1)
22) The electron spin quantum number can have values of
A) -1/2, -1, 0, +1, +1/2.
B) -1/2, -1, +1, +1/2.
C) -1/2, 0, +1/2.
D) -1/2, +1/2.
E) only +1/2.
23) What is the atomic number of a neutral atom that has an electron configuration of 1s2 2s2
2p6 3s2 3p2?
A) 5
B) 11
C) 14
D) 20
24) If ℓ = 4, which one of the following is a possible quantum number for n?
A) 0
B) 2
C) 3
D) 4
E) 8
25) If n = 5, which one of the following is not an allowed magnetic quantum number m1?
A) 0
B) 2
C) 4
D) 5
26) In its ground state, the quantum numbers (n, ℓ, m1, ms) for hydrogen are, respectively,
A) 1, 1, 1, 1.
B) 1, 0, 0, 0.
C) 1, 0, 0, ±1/2.
D) 1, 1, 1, ±1/2.
27) Consider ground-state helium having two electrons in orbit. If one of the electrons has
quantum numbers (n, ℓl, m1, ms) of 1, 0, 0, -1/2 respectively, the quantum numbers for the other
electron will be
A) 1, 1, 0, -1/2.
B) 1, 0, 0, +1/2.
C) 1, 1, 1, +1/2.
D) none of the given answers.
28) The elements in the periodic table that have completely filled shells or subshells are referred
to as
A) noble gases.
B) halogens.
C) alkali metals.
D) transition elements.
29.2 Problems
1) One of the emission lines described by the original version of Balmer’s formula has
wavelength What is the value of n in Balmer’s formula that gives this emission line?
A) 11
B) 12
C) 13
D) 14
2) What is the value of n in the Balmer series for which the wavelength is 410.2 nm.
A) 4
B) 5
C) 6
D) 7
E) 9
3) What is the wavelength in the Balmer series for n = 15?
A) 277.1 nm
B) 371.1 nm
C) 188.6 nm
D) 656 nm
E) 754.2 nm
4) The value of a wavelength in the Balmer series is 372.1 nm. What is the corresponding value
of n?
A) 6
B) 3
C) 9
D) 10
E) 14
5) What is the longest wavelength in the Balmer series?
A) 240 nm
B) 328 nm
C) 365 nm
D) 656 nm
E) 820 nm
6) What is the shortest wavelength in the Balmer series?
A) 328 nm
B) 365 nm
C) 456 nm
D) 656 nm
E) 820 nm
7) What value of n corresponds to a wavelength of 922.7 nm in the Paschen series?
A) 3
B) 5
C) 7
D) 9
E) 15
8) What value of n corresponds to a wavelength of 91.7 nm in the Lyman series?
A) 1
B) 3
C) 5
D) 9
E) 13
9) What is the longest wavelength in the Paschen series?
A) 2.01 nm
B) 2.01 μm
C) 365 nm
D) 1.88 nm
E) 1.88 μm
10) What is the shortest wavelength in the Paschen series?
A) 410.2 nm
B) 410.2 μm
C) 365 nm
D) 820.4 nm
E) 820.4 μm
11) What is the shortest wavelength of the Lyman series?
A) 91.16 nm
B) 45.60 nm
C) 121.5 nm
D) 204.1 nm
E) 365 nm
12) What is the longest wavelength in the Lyman Series?
A) 45.60 nm
B) 91.20 nm
C) 121.5 nm
D) 240.1 nm
E) 365 nm
13) The wavelength of a ruby laser is 694.3 nm. What is the energy difference between the two
energy states for the transition that produces this light? (c = 3.00 × 108 m/s, 1 eV = 1.60 × 10-19
J, h = 6.626 × 10-34 J ∙ s)
A) 1.54 eV
B) 1.65 eV
C) 1.79 eV
D) 1.81 eV
14) What is the energy (in electron-volts) of the n = 3 state of atomic hydrogen?
15) Given that the energy levels of the hydrogen atom are given by En = , where R = 1.097 ×
107 m-1, what wavelength photon is emitted when the atom undergoes a transition from the n =
4 to the n = 6 level?
16) Consider the Bohr model for the hydrogen atom. (c = 3.00 × 108 m/s, 1 eV = 1.60 × 10-19 J,
h = 6.626 × 10-34 J ∙ s)
(a) How much energy (in eV) is needed to cause a transition of an electron from the second
excited state to the third excited state?
(b) What wavelength photon just has enough energy to initiate the transition in (a)?
17) Given that the binding energy of the hydrogen atom in its ground state is -13.6 eV, what is
the energy when it is in the n = 5 state?
A) 2.72 eV
B) -2.72 eV
C) 0.544 eV
D) -0.544 eV
18) If a hydrogen atom in the ground state absorbs a photon of energy 12.09 eV, to which state
will the electron make a transition?
A) n = 2
B) n = 3
C) n = 4
D) n = 5
19) What is the ionization energy of the neutral hydrogen atom?
A) 27.2 eV
B) 13.6 eV
C) 6.8 eV
D) none of the given answers
20) What is the energy of the photon emitted when an electron drops from the state to the
state in a hydrogen atom?
A) 0.244 eV
B) 0.264 eV
C) 0.283 eV
D) 0.303 eV
21) In a hydrogen atom, the electron makes a transition from the n = 8 to the n = 3 state. The
wavelength of the emitted photon is closest to which one of the following values? (c = 3.00 ×
108 m/s, 1 eV = 1.60 × 10-19 J, h = 6.626 × 10-34 J ∙ s)
A) 9.57 × 10-7 m
B) 1.13 × 10-6 m
C) 3.12 × 10-7 m
D) 4.52 × 10-6 m
E) 6.34 × 10-7 m
22) A hydrogen atom is excited to the n = 11 level. Its decay to the n = 7 level is detected in a
photographic plate. What is the wavelength of the light photographed? (c = 3.00 × 108 m/s, 1 eV
= 1.60 × 10-19 J, h = 6.626 × 10-34 J ∙ s)
A) 7510 nm
B) 4670 nm
C) 12,400 nm
D) 4380 nm
23) A hydrogen atom is excited to the n = 9 level. Its decay to the n = 6 level detected in a
photographic plate. What is the frequency of the light photographed? (1 eV = 1.60 × 10-19 J, h =
6.626 × 10-34 J ∙ s)
A) 5.08 × 1013 Hz
B) 5910 Hz
C) 5910 nm
D) 3.28 × 10-9 km
24) A hydrogen atom is in its n = 2 excited state when its electron absorbs in an interaction
with a photon. What is the energy of the resulting free electron?
A) 6.1 eV
B) 7.9 eV
C) 8.2 eV
D) 9.2 eV
25) A hydrogen atom makes a downward transition from the state to the state. Find
the wavelength of the emitted photon. (c = 3.00 × 108 m/s, 1 eV = 1.60 × 10-19 J, h = 6.626 ×
10-34 J ∙ s)
A) 2.56 μm
B) 1.54 μm
C) 2.05 μm
D) 3.07 μm
26) The longest wavelength photon that can be emitted by a hydrogen atom, for which the final
state is is closest to which one of the following values? (c = 3.0 × 108 m/s,
A) 39,000 nm
B) 22,000 nm
C) 7400 nm
D) 16,000 nm
E) 28,000 nm
27) The shortest wavelength of a photon that can be emitted by a hydrogen atom, for which the
initial state is is closest to which one of the following values?
A) 92 nm
B) 82 nm
C) 72 nm
D) 62 nm
E) 52 nm