23. In Rutherford’s model, negatively charged electrons surround a dense, positively charged
nucleus. in Bohr’s model, the electrons are assigned to concentric circular orbits of fixed energy.
24. In an atom, the electrons can only exist in certain fixed energy levels. To move from one
energy level to another requires the emission or absorption of an exact amount of energy, or
quantum.
25. The quantum mechanical model of the atom states the electrons have fixed energy levels.
Electrons are in orbitals that may be visualized as clouds of various shapes, located at different
distances from the nucleus.
26. The 1s orbital is spherical. The 2s orbital is spherical with a diameter larger than that of the
1s orbital. The 2p orbital is dumbbell shaped.
27. The Aufbau principle states that electrons occupy the lowest possible energy levels. The
Pauli exclusion principle states that an atomic orbital can hold a maximum of two electrons.
Hund’s rule states that one electron occupies each of a set of orbitals with equal energies
before any pairing of electrons occurs.
28. a. 1s22s22p63s23p3
b. 1s22s22p63s23p2
c. 1s22s22p5
d. 1s22s22p63s23p6
29. The p orbitals in the third quantum level have three electrons.
30. a. 1s22s22p2
b. 1s22s22p63s23p6
c. 1s22s22p5
d. 1s22s22p63s23p64s23d104p65s1
31. a. correct b. incorrect c. incorrect d. correct
32. a. 8 b. 8 c.8
33. a. 2 b. 1 c. 3
34. a. 2 b. 6 c. 2 d. 10 e. 6 f. 2 g. 14 h. 6
35. 1s22s22p63s23p64s23d104p4
b. 1s22s22p63s23p64s23d3
c. 1s22s22p63s23p64s23d8
d. 1s22s22p63s23p64s2
e. 1s22s22p4
36. The 4s orbital is lower in energy than the 3d orbital.
37. d, a ,e, b, c
38. a. The distance from crest to crest of a wave.
b. The height of a wave.
c. The distance from two consecutive origins of a wave.
39. 6.7 x 10-14 m; shorter wavelength than red light
40. 2.61 x 104 cm
41. Planck showed that radiation is emitted and absorbed in quanta, dependent on the
frequency of radiation.
42. a. Electrons are emitted with a low velocity.
b. More electrons are emitted; velocity stays low.
c. Electrons emitted have higher velocity.
43. A photon is a quantum of light energy. A quantum is a discrete amount of energy.
44. The outermost electron of sodium absorbs photons of wavelength 589 nm, as it jumps to a
higher orbital.
45. 1.3 x 10-38 m
46. Refer to Concept Map on the interleaf page 322B.
47. a. Ar b. Ru c. Gd
48. 1s22s22p63s23p64s23d104p3
The first three energy levels are full; the fourth energy level is partially filled.
49. a. 2
b. 4
c. 10
d. 6
50. 1s22s22p3 nitrogen; 3 unpaired electrons.
51. 7.64 x 10-19 J
52. a. 4.36 x 10-5 cm
b. visible
c. 6.88 x 1014s-1
53. 3.08 x 10-19 J; lower energy
54. a. Na, sodium
b. N, nitrogen
c. Si, silicon
d. O, oxygen
e. K, potassium
f. Ti, titanium
55. a. 1
b. 4
c. 1
56. Answers will vary. Some students may note that radio waves have the lowest energy in the
electromagnetic spectrum, and thus would not energetic enough to cook food. Others may
reason that if microwaves cook food faster than infrared radiation, than radio waves would cook
food even faster.
57. The model of the atom uses the abstract idea of probability; light is considered a particle and
a wave at the same time. Atoms and light cannot be familiar objects or observations because
humans cannot observe atoms or photons directly, and because matter and energy behave
differently at the atomic level than at the level humans can observe directly.
58. 4.06 x 10-10 m, 4.06 x 10-4 μm. The units differ in size.
59. a. 46.8% Si, 53.2% O
b. 34.4% Fe, 65.6% Cl
c. 11.1% H, 88.9% O
d. 2.1% H, 32.7% S, 65.2% O
60. a. 2, 1, 1, 2
b. 1, 1, 2, 1
c. 2, 1, 2
61. 12.5 L
62. a. Fe3+
b. Hg2+
c. HCO3d. O263. a. 55 protons, 55 electrons
b. 47 protons, 46 electrons
c. 48 protons, 46 electrons
d. 34 protons, 36 electrons
64. 1.47 kPa
65. 154 g; 0.154 kg
66. 6.93 x 102 s
67. a. frequency(s-1)
5.20 x 1012
4.40 x 1013
9.50 x 1013
1.70 x 1014
2.20 x 1014
4.70 x 1014
b.See Mrs. Stowell
c. 6.3 x 10-34 J s
d. The slope is Planck’s constant.
68. Outermost electrons are ejected first. Next, electrons at lower energy levels, requiring
greater escape energy, are ejected.
69. H:1312 kJ/ mol(n=1); 328 kJ(n=2) Li2+: 11.00 kJ(n=1)
70. By examining the spectra of the light emitted by the star.
71, All the colors are reproduced from black and three additional colors: magenta, cyan, and
yellow.
72. Each depends on the interaction of electromagnetic radiation with matter.