Introduction to Chemistry, 4e (Russo)
Chapter 4 The Modern Model of the Atom
4.1 Multiple-Choice Questions
1) What is the main difference between "classical physics" and "quantum physics"?
A) Quantum physics requires the speed of light to be a constant value.
B) Classical physics requires that only certain, allowed values for energy be used.
C) Quantum physics requires that only certain, allowed values for energy be used.
D) Quantum physics can only describe the behavior of very small objects, like atoms and molecules.
Answer: C
Topic: Section 4.2
2) For the electron of a hydrogen atom, which of the following quantum "jumps" requires the most
energy?
A) from n = 3 to n = 4
B) from n = 2 to n = 3
C) from n = 4 to n = 5
D) from n = 1 to n = 2
Answer: D
Topic: Section 4.4
3) Which feature of Bohr's atomic model is no longer accepted as true by today's scientists?
A) that most of an atom's mass is located within the nucleus
B) that electrons have only certain, allowed energy values
C) that electrons orbit the nucleus in circular paths
D) that each principal quantum level can hold a maximum of 2n 2 electrons
Answer: C
Topic: Section 4.3
4) Which of the following subshells does not appear in the third shell?
A) s
B) p
C) d
D) f
Answer: D
Topic: Section 4.5
5) Which of the following subshells appear in the second shell?
A) s
B) s,p
C) s, p, d
D) p
Answer: B
Topic: Section 4.5
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6) The correct order of increasing energy in the following subshells is:
A) 2p, 3s, 4s, 3p, 3d
B) 2p, 3s, 3p, 4s, 3d
C) 2p, 3s, 3p, 3d, 4s
D) 2p, 3s, 3d, 3p, 4s
Answer: B
Topic: Section 4.5
7) How many electrons can be "stored" in a completely filled 4f sublevel?
A) 14
B) 10
C) 7
D) 28
Answer: A
Topic: Section 4.5
11) The total number of electrons that can be accommodated in 3d is ________.
A) 5
B) 2
C) 6
D) 10
Answer: D
Topic: Section 4.6
13) Which of the following anions will have the electronic configuration 1s 22s22p63s23p6 ?
A) K1B) Cl1C) S2D) Br1Answer: B
Topic: Section 4.7
15) The likely formula of the compound formed between Ca and O is ________.
A) Ca2O
B) CaO2
C) Ca2O3
D) CaO
Answer: D
Topic: Section 4.7
16) Which of the following elements never obeys the octet rule?
A) Hydrogen
B) Nitrogen
C) Carbon
D) Chlorine
Answer: A
Topic: Section 4.7
17) Which is the correct electronic configuration for Se (atomic number 34) in the ground state?
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A) 1s22s22p63s23p63d104s24p4
B) 1s22s22p63s23p63d104s04p6
C) 1s22s22p63s23p64s23d104p4
D) 1s22s22p63s23p63d104s03p6
Answer: C
Topic: Section 4.5
19) Which of the following species does not match the electronic configuration
1s22s22p63s23p64s23d104p6 ?
A) BrB) Sr+2
C) As-3
D) Se+2
Answer: D
Topic: Section 4.7
20) Which species has the following electronic configuration: 1s 22s22p63s23p6 ?
A) FB) Mg+2
C) P-3
D) SAnswer: C
Topic: Section 4.7
22) Which of the following does not have the neon electron configuration?
A) S4+
B) Mg2+
C) O2D) Al3+
Answer: A
Topic: Section 4.7
23) The scientist credited with developing the current mathematical model of the atom is ________.
A) Bohr
B) Schrodinger
C) Planck
D) Rutherford
Answer: B
Topic: Section 4.8
24) Which of the following does not include [Kr] in its shorthand electron configuration?
A) Sr2+
B) Te2C) Se6+
D) Mo
Answer: C
Topic: Section 4.7
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25) Atoms in which of the following groups will likely gain three electrons?
A) IIIA
B) VA
C) VIIA
D) both A and B
Answer: B
Topic: Section 4.7
27) The relative ratio of atoms in the binary compound Al xOy is ________.
A) x=2, y=3
B) x=3, y=2
C) x=5, y=2
D) x=2, y=5
Answer: A
Topic: Section 4.7
28) The size of boron is ________ than that of oxygen and ________ than that of aluminum.
A) smaller; larger
B) larger; larger
C) smaller; smaller
D) larger; smaller
Answer: D
Topic: Section 4.6
29) Which orbital is dumbbell-shaped?
A) 2s
B) 3p
C) 4d
D) 5g
Answer: B
Topic: Section 4.8
30) Which orbital is a spherical shape?
A) 2s
B) 3p
C) 4d
D) 5f
Answer: A
Topic: Section 4.8
31) What is the number of outer shell electrons in fluorine?
A) 2
B) 5
C) 7
D) 9
Answer: C
Topic: Section 4.5
32) How many valence electrons are in silicon?
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A) 2
B) 4
C) 5
D) 7
Answer: B
Topic: Section 4.5
33) The valence shell ________.
A) always contains eight electrons
B) is the lowest energy shell in an atom
C) is the outermost occupied shell in an atom
D) is always the same for anions and cations
Answer: C
Topic: Section 4.7
34) Below are four pairs of atoms and ions. In which pair is the larger of the two species written first?
A) S2- and S
B) Cu2+ and Cu
C) O and O2D) Cr3+ and Cr
Answer: A
Topic: Section 4.7
35) The ion that has 14 protons and 18 electrons is ________.
A) Si4+
B) Si4C) N4+
D) N4Answer: B
Topic: Section 4.7
36) Which of the following has attained a noble gas electronic configuration?
A) Si4+
B) Cl1+
C) Al3D) Cr3+
Answer: A
Topic: Section 4.7
37) Which color light is composed of photons having the largest energy?
A) blue
B) green
C) yellow
D) red
Answer: A
Topic: Section 4.1
38) Which type of electromagnetic radiation is composed of photons having the largest energy?
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A) microwaves
B) radio waves
C) x rays
D) gamma rays
Answer: D
Topic: Section 4.1
40) The elements of Group VIIIA are almost entirely non-reactive with any of the other chemical
elements. Which of the following statements best explains this observed behavior?
A) Group VIIIA elements comply with the octet rule.
B) Group VIIIA elements are so rare that no one has ever studied their reactive properties in any detail.
C) Group VIIIA elements are all gases, and gases are generally non-reactive.
D) No explanation given here can explain why Group VIIIA elements do not react with any of the other
chemical elements.
Answer: A
Topic: Section 4.7
41) What is the trend in atomic size in the series of Group IIA elements Be through Ra?
A) Atomic size increases in this series.
B) Atomic size decreases in this series.
C) Atomic size remains unchanged in this series.
D) Atomic size increases at first, then decreases in this series.
Answer: A
Topic: Section 4.6
42) Predict the formula of the compound produced in a reaction between barium (Ba) and oxygen (O).
A) BaO2
B) BaO
C) BaO2
D) Ba2O3
Answer: B
Topic: Section 4.7
43) Predict the formula of the compound produced in a reaction between lithium (Li) and phosphorus
(P).
A) LiP
B) Li2P3
C) LiP2
D) Li3P
Answer: D
Topic: Section 4.7
44) What is the wavelength (in meters) of radio waves that have a frequency of 89.9 MHz?
(wavelength × frequency = speed of light; speed of light = 3 × 10 8 meters/sec.)
A) 3.34 centimeters
B) 2.70 × 1016 millimeters
C) 0.300 meters
D) 3.34 meters
Answer: D
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Topic: Section 4.1
45) Calculate the energy in joules of microwave radiation of wavelength 12.7 centimeters.
(E = hν, h = 6.63 × 10-34 J sec; speed of light = wavelength × ν, speed of light = 3 × 10 8 meters/sec.)
A) 4.87 × 1019 J
B) 7.30 × 10-19 J
C) 3.61 × 10-18 J
D) 1.56 × 10-24 J
Answer: D
Topic: Section 4.1
46) In a single atom, what is the maximum number of electrons that can have quantum number n=4?
A) 10
B) 14
C) 18
D) 32
Answer: D
Topic: Section 4.3
47) The units of h (Planck's constant) are ________.
A) J.s
B) J/s
C) m/s
D) J/nm
Answer: A
Topic: Section 4.1
49) Which of the following elements is the smallest size chalcogen?
A) H
B) N
C) O
D) F
Answer: C
Topic: Section 4.8
50) Which of the following elements is the largest size halogen?
A) He
B) Br
C) F
D) Kr
Answer: B
Topic: Section 4.7
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4.2 True/False Questions
1) Bohr's atomic theory places an atom's electrons in discrete-energy circular paths around a central,
positively charged nucleus.
Answer: TRUE
Topic: Section 4.3
3) The only possible way for an excited state electron to return to the ground state is to emit energy in the
form of visible light.
Answer: FALSE
Topic: Section 4.1
4) Atoms tend to increase in size as one moves from left to right across a period.
Answer: FALSE
Topic: Section 4.6
6) The f-block represents a region on the periodic table which is 10 elements in width.
Answer: FALSE
Topic: Section 4.5
7) The p-block represents a region on the periodic table which is 6 elements in width.
Answer: TRUE
Topic: Section 4.5
8) The n = 5 principal energy level can hold a maximum of 25 electrons.
Answer: FALSE
Topic: Section 4.5
9) The s-type orbitals of any given principal energy level are always spherical in shape.
Answer: TRUE
Topic: Section 4.8
11) The atomic radius can be calculated by x-ray diffraction.
Answer: TRUE
Topic: Section 4.6
12) Modern scientists accept the notion that electrons are found in circular orbits around a central,
positively charged nucleus.
Answer: FALSE
Topic: Section 4.8
14) Should an oxygen atom (O) gain two electrons, it would then have the same ground state electronic
configuration as an atom of neon (Ne), thus satisfying the octet rule.
Answer: TRUE
Topic: Section 4.7
15) A non-metal is an element that tends to gain valence electrons in chemical reactions becoming a cation
in the process.
Answer: FALSE
Topic: Section 4.7
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16) The atom size decreases as one proceeds from left to right across a period.
Answer: TRUE
Topic: Section 4.6
18) +1 is the only charge sodium ions normally have.
Answer: TRUE
Topic: Section 4.6
19) The element is defined by its atomic number.
Answer: TRUE
Topic: Section 4.1
20) If an element has a small electron affinity value it can easily lose an electron.
Answer: FALSE
Topic: Section 4.6
21) Halogens have large electron affinity values.
Answer: TRUE
Topic: Section 4.6
22) H+ has one electron.
Answer: FALSE
Topic: Section 4.7
23) The wavelength is the distance measured between two crests, but not between two troughs.
Answer: FALSE
Topic: Section 4.1
24) Carbon can assume both +4 and -4 charges.
Answer: TRUE
Topic: Section 4.7
25) The speed of light is about 186,000 miles per minute.
Answer: FALSE
Topic: Section 4.1
26) Shells get larger as the principal quantum number n increases.
Answer: TRUE
Topic: Section 4.8
27) The number of electrons in the valence shell of an atom is equal to the group number for the
representative elements.
Answer: TRUE
Topic: Section 4.5
28) Once an atom gets excited, it may remain in that excited state indefinitely.
Answer: FALSE
Topic: Section 4.4
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29) An electron in the excited state does not necessarily return to a ground state in a single jump.
Answer: TRUE
Topic: Section 4.4
30) The 95% boundary indicates the area where 95% of the time the electron may be found.
Answer: TRUE
Topic: Section 4.8
31) Both the energy and the wavelength of electromagnetic radiation are related by the constants c, the
speed of light, and Planck's constant, h.
Answer: TRUE
Topic: Section 4.1
34) Microwave is radiation of a lower energy than that of visible light.
Answer: TRUE
Topic: Section 4.1
35) The red light is the element that possesses the lowest frequency of the visible region of the
electromagnetic spectrum.
Answer: TRUE
Topic: Section 4.1
36) The frequency of infrared radiation that has a wavelength of 1.5 × 10 3 nm is 2.0 × 107 sec-1
(given: speed of light = 3.0 × 108 m/sec).
Answer: FALSE
Topic: Section 4.1
37) The wavelengths in infrared radiation are larger than those of the ultraviolet region.
Answer: TRUE
Topic: Section 4.1
4.3 Short Answer Questions
1) Write the complete electronic ground state configuration for tellurium (Te). Make sure the terms in
your answer are listed in order of increasing energy.
Answer: Two possible, equally correct answers: the abbreviated [Kr] 5s 24d105p4, or the
complete 1s22s22p63s23p64s23d104p65s24d105p4 .
Topic: Section 4.5
2) Which element is the more reactive, sodium (Na) or potassium (K)?
Answer: Potassium (K), as it possesses a more accessible, single valence electron by virtue of its larger
size. This lone electron is found farther from the nucleus in potassium than sodium, and is easier to
remove, making it more reactive.
Topic: Section 4.7
3) Write the complete electronic ground state configuration of the Se 2- ion. Which other element (if any)
shares this electronic configuration?
Answer: Se : 1s22s22p63s23p64s23d104p6. This is the same electronic configuration as the element
krypton (Kr).
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Topic: Section 4.7
4) List the sublevels of the n = 3 principal energy level, and state the maximum number of electrons
contained within each of these sublevels.
Answer: n = 3: 3s, containing 2 electrons
3p, containing 6 electrons
3d, containing 10 electrons
Topic: Section 4.5
4.4 Matching Questions
Match each element with the most likely valence charge of its ion in the list below.
A) (-1)
B) (-2)
C) (+2)
D) (+3)
E) (-3)
F) (+1)
G) zero
H) (+4 or -4)
1) Li
Topic: Section 4.7
2) O
Topic: Section 4.7
3) S
Topic: Section 4.7
4) C1
Topic: Section 4.7
5) Si
Topic: Section 4.7
6) Ba
Topic: Section 4.7
7) N
Topic: Section 4.7
8) Br
Topic: Section 4.7
9) K
Topic: Section 4.7
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10) Ne
Topic: Section 4.7
11) Al
Topic: Section 4.7
12) P
Topic: Section 4.7
13) H
Topic: Section 4.7
14) I
Topic: Section 4.7
15) He
Topic: Section 4.7
Answers: 1) F 2) B 3) B 4) A 5) H 6) C 7) E 8) A 9) F 10) G
11) D 12) E 13) F 14) A 15) G
Match the following species with the corresponding electronic configuration from the list below.
A) 1s22s22p63s23p6
B) 1s22s22p63s23p1
C) 1s22s22p63s2
D) 1s22s22p63s23p5
E) 1s22s22p63s23p4
F) 1s22s22p6
G) 1s22s22p63s23p3
H) 1s22s22p63s23p2
16) Mg2+
Topic: Section 4.7
17) Ca2+
Topic: Section 4.7
18) Al
Topic: Section 4.7
19) P
Topic: Section 4.7
20) Si4+
Topic: Section 4.7
21) Si412
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Topic: Section 4.7
22) C15+
Topic: Section 4.7
23) S
Topic: Section 4.7
24) S+4
Topic: Section 4.7
25) S6+
Topic: Section 4.7
26) S2Topic: Section 4.7
27) N3Topic: Section 4.7
28) Si
Topic: Section 4.7
29) C1
Topic: Section 4.7
Answers: 16) F 17) A 18) B 19) G 20) F 21) A 22) C 23) E 24) C 25) F 26) A 27) F 28) H 29) D
Match the outermost occupied orbital(s) with the corresponding element from the list below.
A) Sr
B) Dy
C) Th
D) Cu
E) Xe
F) Br
G) Mn
30) 5s2
Topic: Section 4.5
31) 4p5
Topic: Section 4.5
32) 3d5
Topic: Section 4.5
33) 4s13d10
Topic: Section 4.5
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34) 5p6
Topic: Section 4.5
35) 6s24f10
Topic: Section 4.5
36) 7s26d2
Topic: Section 4.5
Answers: 30) A 31) F 32) G 33) D 34) E 35) B 36) C
Classify each of the following as ground state, excited state, or impossible electronic configurations.
A) Excited State
B) Impossible state
C) Ground State
37) 1s22s22p63s13p3
Topic: Section 4.5
38) 1s22s22p63s23p8
Topic: Section 4.5
39) 1s22s22p63s23p64s1
Topic: Section 4.5
40) 1s22s22p63s23p64s24p1
Topic: Section 4.5
41) 1s22s22p63s23p64s23d5
Topic: Section 4.5
42) 1s22s22p63s23p64s13d104p1
Topic: Section 4.5
43) 1s22s22p63s23p64s23d12
Topic: Section 4.5
Answers: 37) A 38) B 39) C 40) A 41) C 42) A 43) B
Match the scientist with his contribution from the list below.
A) Is the father of quantum physics
B) Suggested the existence of a tiny, massive nucleus
C) First described the quantum theory of energy
D) Proposed the quantized energy of electrons
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44) Niels Bohr
Topic: Section 4.8
45)Ernest Rutherford
Topic: Section 4.8
46)Erwin Schrodinger
Topic: Section 4.8
47)Max Planck
Topic: Section 4.8
Answers: 44) C 45) B 46) A 47) D
Match every binary compound in the first column with the correct coefficient of x and y in the second column.
A) x = 1, y = 3
B) x = 4, y = 1
C) x = 2, y = 3
D) x = 1, y = 1
E) x = 1, y = 2
F) x = 3, y = 1
G) x = 3, y = 2
H) x = 3, y = 4
I) x = 2, y = 1
J) x = 1, y = 4
48) AlxCly
Topic: Section 4.7
49) NaxSy
Topic: Section 4.7
50) MgxOy
Topic: Section 4.7
51) CaxNy
Topic: Section 4.7
52) CxCly
Topic: Section 4.7
53) LixCy
Topic: Section 4.7
54) AlxSy
Topic: Section 4.7
55) PxHy
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Topic: Section 4.7
56) CxOy
Topic: Section 4.7
57) LixNy
Topic: Section 4.7
58) CxNy
Topic: Section 4.7
59) BxFy
Topic: Section 4.7
60) BaxCly
Topic: Section 4.7
61) LixHy
Topic: Section 4.7
Answers: 48) A 49) I 50) E 51) G 52) J 53) B 54) C 55) A 56) E 57) F 58) H 59) A 60) E 61) D
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