1) There are __________ paired and __________ unpaired electrons in the Lewis symbol for a
phosphorus atom.
A) 4, 2
B) 2, 4
C) 2, 3
D) 4, 3
E) 0, 3
Answer: C
Diff: 1
Page Ref: Sec. 8.1
3) Based on the octet rule, magnesium most likely forms a __________ ion.
A) Mg 2
B) Mg 2
C) Mg 6
D) Mg 6
E) Mg _
Answer: A
Diff: 1
Page Ref: Sec. 8.1
10) The halogens, alkali metals, and alkaline earth metals have __________ valence electrons,
respectively.
A) 7, 4, and 6
B) 1, 5, and 7
C) 8, 2, and 3
D) 7, 1, and 2
E) 2, 7, and 4
Answer: D
Diff: 2
Page Ref: Sec. 8.1
14) For a given arrangement of ions, the lattice energy increases as ionic radius __________ and
as ionic charge __________.
A) decreases, increases
B) increases, decreases
C) increases, increases
D) decreases, decreases
E) This cannot be predicted.
Answer: A
Diff: 1
Page Ref: Sec. 8.2
24) A __________ covalent bond between the same two atoms is the longest.
A) single
B) double
C) triple
D) They are all the same length.
E) strong
Answer: A
Diff: 1
Page Ref: Sec. 8.3
23) How many single covalent bonds must a silicon atom form to have a complete octet in its
valence shell?
A) 3
B) 4
C) 1
D) 2
E) 0
Answer: B
Diff: 1
Page Ref: Sec. 8.3
26) A double bond consists of __________ pairs of electrons shared between two atoms.
A) 1
B) 2
C) 3
D) 4
E) 6
Answer: B
Diff: 2
Page Ref: Sec. 8.3
27) What is the maximum number of double bonds that a hydrogen atom can form?
A) 0
B) 1
C) 2
D) 3
E) 4
Answer: A
Diff: 1
Page Ref: Sec. 8.3
29) In the molecule below, which atom has the largest partial negative charge __________?
A) Cl
B) F
C) Br
D) I
E) C
Answer: B
Diff: 1
Page Ref: Sec. 8.4
30) The ability of an atom in a molecule to attract electrons is best quantified by the
__________.
A) paramagnetism
B) diamagnetism
C) electronegativity
D) electron change-to-mass ratio
E) first ionization potential
Answer: C
Diff: 1
Page Ref: Sec. 8.4
31) Given the electronegativities below, which covalent single bond is most polar?
Element:
H
C
N
O
Electronegativity:
2.1
2.5
3.0 3.5
A) C-H
B) N-H
C) O-H
D) O-C
E) O-N
Answer: C
Diff: 1
Page Ref: Sec. 8.4
32) Electronegativity __________ from left to right within a period and __________ from top to
bottom within a group.
A) decreases, increases
B) increases, increases
C) increases, decreases
D) stays the same, increases
E) increases, stays the same
Answer: C
Diff: 1
Page Ref: Sec. 8.4
38) The Lewis structure of HCN (H bonded to C) shows that __________ has __________
nonbonding electron pairs.
A) C, 1
B) N, 1
C) H, 1
D) N, 2
E) C, 2
Answer: B
Diff: 2
Page Ref: Sec. 8.5
39) The formal charge on carbon in the molecule below is __________.
A) 0
B) +1
C) +2
D) +3
E) -1
Answer: A
Diff: 1
Page Ref: Sec. 8.5
43) In the resonance form of ozone shown below, the formal charge on the central oxygen atom
is __________.
A) 0
B) +1
C) -1
D) +2
E) -2
Answer: B
Diff: 1
Page Ref: Sec. 8.6
44) How many equivalent resonance forms can be drawn for CO 3 2  - (carbon is the central
atom)?
A) 1
B) 2
C) 3
D) 4
E) 0
Answer: C
Diff: 1
Page Ref: Sec. 8.6
47) How many different types of resonance structures can be drawn for the ion SO32 where all
atoms satisfy the octet rule?
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: A
Diff: 2
Page Ref: Sec. 8.6
48) Using the table of average bond energies below, the H for the reaction is __________ kJ.
Bond:
D (kJ/mol):
C≡C
839
C-C
348
H-I
299
C-I
240
C-H
413
A) +160
B) -160
C) -217
D) -63
E) +63
Answer: C
Diff: 1
Page Ref: Sec. 8.8
51) Using the table of bond dissociation energies, the H for the following gas-phase reaction is
__________ kJ.
A) -44
B) 38
C) 304
D) 2134
E) -38
Answer: A
Diff: 1
Page Ref: Sec. 8.8
4) Which of the following does not have eight valence electrons?
A) Ca 
B) Rb 
C) Xe
D) Br 
E) All of the above have eight valence electrons.
Answer: A
Diff: 3
Page Ref: Sec. 8.1
7) In ionic bond formation, the lattice energy of ions ________ as the magnitude of the ion
charges _______ and the radii __________.
A) increases, decrease, increase
B) increases, increase, increase
C) decreases, increase, increase
D) increases, increase, decrease
E) increases, decrease, decrease
Answer: D
Diff: 3
Page Ref: Sec. 8.2
5) The chloride of which of the following metals should have the greatest lattice energy?
A) potassium
B) rubidium
C) sodium
D) lithium
E) cesium
Answer: D
Diff: 2
Page Ref: Sec. 8.2
10) The electron configuration [Kr]4d10 represents __________.
A) Sr+2
B) Sn+2
C) Te+2
D) Ag+1
E) Rb+1
Answer: D
Diff: 3
Page Ref: Sec. 8.2
13) The type of compound that is most likely to contain a covalent bond is __________.
A) one that is composed of a metal from the far left of the periodic table and a nonmetal from the
far right of the periodic table
B) a solid metal
C) one that is composed of only nonmetals
D) held together by the electrostatic forces between oppositely charged ions
E) There is no general rule to predict covalency in bonds.
Answer: C
Diff: 1
Page Ref: Sec. 8.3
14) In which of the molecules below is the carbon-carbon distance the shortest?
A) H2C  CH2
B) H  C  C  H
C) H3C  CH3
D) H2C  C  CH2
E) H3C  CH2  CH3
Answer: B
Diff: 1
Page Ref: Sec. 8.3
15) Of the atoms below, __________ is the most electronegative.
A) Br
B) O
C) Cl
D) N
E) F
Answer: E
Diff: 1
Page Ref: Sec. 8.4
21) Which of the following has the bonds correctly arranged in order of increasing polarity?
A) Be  F, Mg  F, N  F, O  F
B) O  F, N  F, Be  F, Mg  F
C) O  F, Be  F, Mg  F, N  F
D) N  F, Be  F, Mg  F, O  F
E) M  gF, Be  F, N  F, O  F
Answer: B
Diff: 1
Page Ref: Sec. 8.4
23) The bond length in an HI molecule is 1.61 Å and the measured dipole moment is 0.44 D.
What is the magnitude (in units of e) of the negative charge on I in HI?
( 1 debye = 3.34 1030 coulomb-meters ; ; e=1.6 1019 coulombs )
A) 1.6 1019
B) 0.057
C) 9.1
D) 1
E) 0.22
Answer: B
Diff: 5
Page Ref: Sec. 8.4
26) The Lewis structure of N 2 H 2 shows __________.
A) a nitrogen-nitrogen triple bond
B) a nitrogen-nitrogen single bond
C) each nitrogen has one nonbonding electron pair
D) each nitrogen has two nonbonding electron pairs
E) each hydrogen has one nonbonding electron pair
Answer: C
Diff: 2
Page Ref: Sec. 8.5
29) The Lewis structure of the CO 3 2  ion is __________.
A)
B)
C)
D)
E)
Answer: A
Diff: 2
Page Ref: Sec. 8.5
31) Resonance structures differ by __________.
A) number and placement of electrons
B) number of electrons only
C) placement of atoms only
D) number of atoms only
E) placement of electrons only
Answer: E
Diff: 1
Page Ref: Sec. 8.6
33) To convert from one resonance structure to another, __________.
A) only atoms can be moved
B) electrons and atoms can both be moved
C) only electrons can be moved
D) neither electrons nor atoms can be moved
E) electrons must be added
Answer: C
Diff: 1
Page Ref: Sec. 8.6
For the questions that follow, consider the BEST Lewis structures of the following oxyanions:
(i) NO 2 
(ii) NO 3 
(iii) SO32
(iv) SO 4 2
(v) BrO 3 
35) There can be four equivalent best resonance structures of __________.
A) (ii)
B) (iii)
C) (i)
D) (iv)
E) (v)
Answer: D
Diff: 2
Page Ref: Sec. 8.5-8.7
45) A valid Lewis structure of __________ cannot be drawn without violating the octet rule.
A) NI3
B) SO 2
C) ICl5
D) SiF4
E) CO2
Answer: C
Diff: 1
Page Ref: Sec. 8.7
1) Using the VSEPR model, the electron-domain geometry of the central atom in BF 3 is
__________.
A) linear
B) trigonal planar
C) tetrahedral
D) trigonal bipyramidal
E) octahedral
Answer: B
Diff: 1
Page Ref: Sec. 9.2
8) Using the VSEPR model, the molecular geometry of the central atom in SO 2 is __________.
A) linear
B) trigonal planar
C) tetrahedral
D) bent
E) trigonal pyramidal
Answer: D
Diff: 1
Page Ref: Sec. 9.2
1) What is the molecular geometry of a molecule that has three bonding and two non-bonding
domains?
Answer: T-shaped
Diff: 4
Page Ref: Sec. 9.2
2) In the valence shell of an atom there are six electron domains. They will be arranged in a (an)
__________ geometry.
Answer: octahedral
Diff: 5
Page Ref: Sec. 9.2
3) What are the three bond angles in the trigonal bipyramidal structure?
Answer: 90 °, 120 °, 180 °
Diff: 4
Page Ref: Sec. 9.2
4) Three molecules have similar electron domains, but different molecular shapes. Why?
Answer: different numbers of non-bonding domains
Diff: 4
Page Ref: Sec. 9.2
5) The 1s hydrogen orbital overlaps with the __________ iodine orbital in HI.
Answer: 5p
Diff: 2
Page Ref: Sec 9.5
6) A covalent bond in which overlap regions lie above and below an internuclear axis is called
a(n) __________.
Answer: π bond
Diff: 2
Page Ref: Sec 9.6
Multiple choice
1) The basis of the VSEPR model of molecular bonding is __________.
A) regions of electron density on an atom will organize themselves so as to maximize s-character
B) regions of electron density in the valence shell of an atom will arrange themselves so as to
maximize overlap
C) atomic orbitals of the bonding atoms must overlap for a bond to form
D) electron domains in the valence shell of an atom will arrange themselves so as to minimize
repulsions
E) hybrid orbitals will form as necessary to, as closely as possible, achieve spherical symmetry
Answer: D
Diff: 1
Page Ref: Sec. 9.2
4) The electron domain and molecular geometry of BrO 2  is _________.
A) tetrahedral, trigonal planar
B) trigonal planar, trigonal planar
C) trigonal pyramidal, linear
D) tetrahedral, bent
E) trigonal pyramidal, seesaw
Answer: D
Diff: 4
Page Ref: Sec. 9.2
7) The O  C  O bond angle in the CO 3 2  ion is approximately __________.
A) 90 °
B) 109.5 °
C) 120 °
D) 180 °
E) 60 °
Answer: C
Diff: 2
Page Ref: Sec. 9.2
9) The molecular geometry of the BrO 3  ion is __________.
A) trigonal pyramidal
B) trigonal planar
C) bent
D) tetrahedral
E) T-shaped
Answer: A
Diff: 2
Page Ref: Sec. 9.2
10) The molecular geometry of the left-most carbon atom in the molecule below is __________.
A) trigonal planar
B) trigonal bipyramidal
C) tetrahedral
D) octahedral
E) T-shaped
Answer: C
Diff: 1
Page Ref: Sec. 9.2
12) The bond angles marked a, b, and c in the molecule below are about __________,
__________, and __________, respectively.
A) 90 °, 90 °, 90 °
B) 120 °, 120 °, 90 °
C) 120 °, 120 °, 109.5 °
D) 109.5 °, 120 °, 109.5 °
E) 109.5 °, 90 °, 120 °
Answer: D
Diff: 2
Page Ref: Sec. 9.2
15) The central iodine atom in the ICl 4  ion has __________ nonbonded electron pairs and
__________ bonded electron pairs in its valence shell.
A) 2, 2
B) 3, 4
C) 1, 3
D) 3, 2
E) 2, 4
Answer: E
Diff: 1
Page Ref: Sec. 9.2
16) The central iodine atom in IF5 has __________ unbonded electron pairs and __________
bonded electron pairs in its valence shell.
A) 1, 5
B) 0, 5
C) 5, 1
D) 4, 1
E) 1, 4
Answer: A
Diff: 1
Page Ref: Sec. 9.2
18) An electron domain consists of __________.
a) a nonbonding pair of electrons
b) a single bond
c) a multiple bond
A) a only
B) b only
C) c only
D) a, b, and c
E) b and c
Answer: D
Diff: 1
Page Ref: Sec. 9.2
27) For molecules of the general formula ABn n can be greater than four __________.
A) for any element A
B) only when A is an element from the third period or below the third period
C) only when A is boron or beryllium
D) only when A is carbon
E) only when A is Xe
Answer: B
Diff: 2
Page Ref: Sec. 9.2
29) Of the molecules below, only __________ is polar.
A) SbF5
B) AsH 3
C) I 2
D) SF6
E) CH4
Answer: B
Diff: 2
Page Ref: Sec. 9.3
34) The molecular geometry of the BeCl2 molecule is __________, and this molecule is
__________.
A) linear, nonpolar
B) linear, polar
C) bent, nonpolar
D) bent, polar
E) trigonal planar, polar
Answer: A
Diff: 1
Page Ref: Sec. 9.3
41) According to valence bond theory, which orbitals overlap in the formation of the bond in
HBr?
A) 1s on H and 4p on Br
B) 1s on H and 4s on Br
C) 1s on H and 3p on Br
D) 2s on H and 4p on Br
E) 2s on H and 3p on Br
Answer: A
Diff: 1
Page Ref: Sec. 9.4
44) The electron-domain geometry of a carbon-centered compound is tetrahedral. The
hybridization of the central carbon atom is __________.
A) sp
B) sp 2
C) sp3
D) sp3d
E) sp3d 2
Answer: C
Diff: 2
Page Ref: Sec. 9.5
45) Of the following, only __________ has sp 2 hybridization of the central atom.
A) PH 3
B) CO 3 2 
C) ICl3
D) I3
E) PF5
Answer: B
Diff: 1
Page Ref: Sec. 9.5
46) Of the following, the central atom is sp3d 2 hybridized only in __________.
A) PCl5
B) XeF4
C) PH 3
D) Br3 
E) BeF2
Answer: B
Diff: 1
Page Ref: Sec. 9.5
50) The hybridizations of iodine in IF3 and IF5 are __________ and __________, respectively.
A) sp3 , sp3d
B) sp3d , sp3d 2
C) sp3d , sp3
D) sp3d 2 , sp3d
E) sp3d 2 , sp3d 2
Answer: B
Diff: 1
Page Ref: Sec. 9.5
51) The hybridizations of bromine in BrF5 and of arsenic in AsF5 are __________ and
__________, respectively.
A) sp3 , sp3d
B) sp3d , sp3d 2
C) sp3d , sp3
D) sp3d 2 , sp3d
E) sp3d 2 , sp3d 2
Answer: D
Diff: 1
Page Ref: Sec. 9.5
52) The hybrid orbitals used for bonding by the sulfur atom in the SF4 molecule are __________
orbitals.
A) sp
B) sp 2
C) sp3
D) sp3d
E) sp3d 2
Answer: D
Diff: 1
Page Ref: Sec. 9.5
61) When three atomic orbitals are mixed to form hybrid orbitals, how many hybrid orbitals are
formed?
A) one
B) six
C) three
D) four
E) five
Answer: C
Diff: 1
Page Ref: Sec. 9.5
62) The blending of one s atomic orbital and two p atomic orbitals produces __________.
A) three sp hybrid orbitals
B) two sp 2 hybrid orbitals
C) three sp3 hybrid orbitals
D) two sp3 hybrid orbitals
E) three sp 2 hybrid orbitals
Answer: E
Diff: 1
Page Ref: Sec. 9.5
68) There are __________ σ bonds and __________ π bonds in
H3C  CH2  CH  CH  CH2  C  CH .
A) 14, 2
B) 10, 3
C) 12, 2
D) 13, 2
E) 16, 3
Answer: E
Diff: 4
Page Ref: Sec. 9.6
69) Which of the following molecules or ions will exhibit delocalized bonding?
SO 2
SO3
SO32
A) SO 2 , SO3 , and SO32
B) SO32 only
C) SO 2 and SO3
D) SO3 and SO32
E) None of the above will exhibit delocalized bonding.
Answer: C
Diff: 1
Page Ref: Sec. 9.6
73) The carbon-carbon σ bond in ethylene, H 2C  C , results from the overlap of __________.
A) sp hybrid orbitals
B) sp3 hybrid orbitals
C) sp 2 hybrid orbitals
D) s atomic orbitals
E) p atomic orbitals
Answer: C
Diff: 1
Page Ref: Sec. 9.6
74) The π bond in ethylene, H2C  CH2 , results from the overlap of __________.
A) sp3 hybrid orbitals
B) s atomic orbitals
C) sp hybrid orbitals
D) sp 2 hybrid orbitals
E) p atomic orbitals
Answer: E
Diff: 1
Page Ref: Sec. 9.6
78) The hybridization of nitrogen in the H  C  N: molecule is __________.
A) sp
B) s2 p
C) s3 p
D) sp 2
E) sp3
Answer: A
Diff: 1
Page Ref: Sec. 9.6
80) The hybridization of the oxygen atom labeled x in the structure below is __________.
A) sp
B) sp 2
C) sp3
D) sp3d
E) sp3d 2
Answer: B
Diff: 1
Page Ref: Sec. 9.6
81) The Lewis structure of carbon dioxide is given below. The hybridization of the carbon atom
in carbon dioxide is __________.
A) sp3
B) sp 2
C) sp
D) sp2d
E) sp 2 d 2
Answer: C
Diff: 2
Page Ref: Sec. 9.6
82) Electrons in __________ bonds remain localized between two atoms. Electrons in
__________ bonds can become delocalized between more than two atoms.
A) pi, sigma
B) sigma, pi
C) pi, pi
D) sigma, sigma
E) ionic, sigma
Answer: B
Diff: 2
Page Ref: Sec. 9.6
86) In molecular orbital theory, the σ orbital is __________ and the σ  orbital is
1s
1s
__________ in the H 2 molecule.
A) filled, filled
B) filled, empty
C) filled, half-filled
D) half-filled, filled
E) empty, filled
Answer: B
Diff: 4
Page Ref: Sec. 9.7
88) Based on molecular orbital theory, the bond order of the H  H bond in the H 2  ion is
__________.
A) 0
B) 1/2
C) 1
D) 3/2
E) 2
Answer: B
Diff: 4
Page Ref: Sec. 9.7
89) An antibonding π orbital contains a maximum of __________ electrons.
A) 1
B) 2
C) 4
D) 6
E) 8
Answer: B
Diff: 3
Page Ref: Sec. 9.7
94) Based on molecular orbital theory, the only molecule in the list below that has unpaired
electrons is __________.
A) C2
B) N 2
C) F2
D) O2
E) Li 2
Answer: D
Diff: 3
99) Based on molecular orbital theory, the bond order of the C  C bond in the C2 molecule is
__________.
A) 0
B) 1
C) 2
D) 3
E) 4
Answer: C
Diff: 4
Page Ref: Sec. 9.8
102) According to MO theory, overlap of two p atomic orbitals produces __________.
A) two bonding molecular orbitals
B) one bonding molecular orbital and one antibonding molecular orbital
C) two bonding molecular orbitals and two antibonding molecular orbitals
D) two bonding molecular orbitals and one antibonding molecular orbital
E) three bonding molecular orbitals and three antibonding molecular orbitals
Answer: B
Diff: 3
Page Ref: Sec. 9.8
103) According to MO theory, overlap of two p atomic orbitals produces __________.
A) one π MO and one σ MO
B) one π MO and one σ MO
C) one π MO and one π MO or one σ MO and one σ MO
D) one π  MO and one σ MO
E) two π MOs, two π  MOs, one σ MO, and one σ MO
Answer: C
Diff: 3
Page Ref: Sec. 9.8
106) The bond order of a homonuclear diatomic molecule can be decreased by __________.
A) removing electrons from a bonding MO or adding electrons to an antibonding MO
B) adding electrons to a bonding MO or removing electrons from an antibonding MO
C) adding electrons to any MO
D) removing electrons from any MO
E) The bond order of a homonuclear diatomic molecule cannot be decreased by any means.
Answer: A
Diff: 4
Page Ref: Sec. 9.8
107) The order of MO energies in B2 , C2 , and N2 (σ2p  π2p) , is different from the order in O2 ,
F2 , and Ne2 (σ2p  π2p) This is due to __________.
A) less effective overlap of p orbitals in O2 , F2, and Ne2
B) the more metallic character of boron, carbon and nitrogen as compared to oxygen, fluorine,
and neon
C) greater 2s-2p interaction in O2 , F2 , and Ne2
D) greater 2s-2p interaction in B2 C2 , and N 2
E) less effective overlap of p orbitals in B2 , C2 , and N 2
Answer: D
Diff: 5
Page Ref: Sec. 9.8