Name: ________________________ Class: ___________________ Date: __________
ID: A
Ch. 6 PT
Multiple Choice
Identify the choice that best completes the statement or answers the question.
1. A charged group of covalently bonded atoms is known as a(n)
a. polyatomic. b. cation. c. anion. d. formula unit.
2. A neutral group of atoms held together by covalent bonds is a
a. polyatomic ion. b. chemical formula. c. molecular formula. d. molecule.
3. A covalent bond is formed when two atoms
a. gain electrons. b. share one or more pairs of electrons with each other. c. share an electron with each other. d. gain
and lose electrons.
4. Multiple covalent bonds may occur in atoms that contain carbon, nitrogen, or
a. hydrogen. b. oxygen. c. helium. d. chlorine.
5. The lattice energy is a measure of the
a. strength of a covalent bond. b. strength of an ionic bond. c. strength of a metallic bond. d. net charge on a crystal.
6. There are __________ valence electrons in the Lewis structure of CH3CH2Cl.
a. 18 b. 20 c. 10 d. 14
7. Alloys are important because
a. they never corrode. b. they are less expensive to produce than their component elements. c. their properties are a blend of their component elements. d. their properties are often superior to those of their component elements.
8. A polar molecule contains
a. a region of positive charge and a region of negative charge. b. only London forces. c. ions. d. no bonds.
9. The ionization energies for removing successive electrons from sodium are 496 kJ/mol, 4562 kJ/mol, 6912 kJ/mol, and 9544
kJ/mol. The great jump in ionization energy after the first electron is removed indicates that
a. the atomic radius has increased. b. sodium has four or five electrons. c. the noble gas configuration has been
reached. d. a d electron has been removed.
10. According to VSEPR theory, if there are three electron domains in the valence shell of an atom, they will be arranged in a(n)
__________ geometry.
a. octahedral b. tetrahedral c. trigonal planar d. trigonal bipyramidal
11. To draw a Lewis structure, one must know the
a. bond length of each atom. b. atomic mass of each atom. c. ionization energy of each atom. d. number of valence
electrons in each atom.
12. The central iodine atom in IF5 has ___ unbonded electron pairs and ___ bonded electron pairs in its valence shell.
a. 1, 5 b. 5, 1 c. 0, 5 d. 4, 1
13. Compared with solid ionic compounds, solid molecular compounds generally
a. are more brittle. b. are harder. c. have lower melting points. d. conduct electricity as liquids.
14. The arrangement of valence electrons in a metallic bond is best described as
a. fixed positions in a lattice. b. electron pairs existing in multiple bonds. c. concentrated electron density around
specific atoms. d. a sea of free-moving electrons.
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Name: ________________________
ID: A
15. Some ionic compounds do not dissolve in water because
a. water molecules cannot fit in the spaces between the ions in the crystal lattice. b. water is a covalent compound and
covalent compounds cannot dissolve ionic compounds. c. the attractions between the water molecules and the ions are not
as strong as the attractions between the ions. d. they are less dense than water and float on the surface.
16. A positive ion is known as a(n)
a. anion b. valence electron. c. cation. d. ionic radius.
17. Sulfur forms an ion with a charge of __________.
a. 2+ b. 6- c. 2- d. 6+
18. VSEPR theory predicts that the shape of carbon tetrachloride, CCl4, is
a. tetrahedral. b. bent. c. trigonal planar. d. linear.
19. Which of these is responsible for the good electrical conductivity of metals?
a. the high density of metals atoms in the crystal lattice b. the fact that metal atoms contain many orbitals separated by
very small energy c. the ability of electrons to move freely about the crystal structure d. the arrangement of metal atoms
in separate layers
20. Orbitals of equal energy produced by the combination of two or more orbitals on the same atom are called
a. bonding orbitals. b. high-energy orbitals. c. valence orbitals. d. hybrid orbitals.
21. When an electron is acquired by a neutral atom, the energy change is called
a. electronegativity. b. electron affinity. c. ionization energy. d. electron configuration.
22. PCl5 has __________ electron domains and a __________ molecular arrangement.
a. 5, trigonal bipyramidal b. 6, trigonal bipyramidal c. 5, square pyramidal d. 6, seesaw
23. In which of the molecules below is the carbon-carbon distance the shortest?
a. H2C C CH2 b. H-CC-H c. H3C-CH2-CH3 d. H2C CH2
24. The valence electrons in a metallic bond
a. are shared equally between two metal atoms. b. continuously move from one energy level to another. c. are held
tightly by the most positively charged atom. d. move freely throughout the network of metal atoms.
25. The central iodine atom in the ICl 4- ion has ____ nonbonded electron pairs and ____ bonded electron pairs in its valence
shell.
a. 3, 2 b. 2, 2 c. 2, 4 d. 1, 3
26. Which of the following diatomic molecules is joined by a double covalent bond?
a. O 2 b. N 2 c. Cl 2 d. He 2
27. Use VSEPR theory to predict the shape of the hydrogen chloride molecule, HCl.
a. linear b. tetrahedral c. bent d. trigonal-planar
28. VSEPR theory
a. predicts the shape of some molecules. b. is limited to polar molecules. c. assumes that pairs of valence electrons
surrounding an atom repel each other. d. Both (a) and (c)
29. The Lewis structure of PF3 shows that the central phosphorus atom has _____ nonbonding and ____ bonding electron pairs.
a. 1, 2 b. 3, 3 c. 3, 1 d. 1, 3
30. When an electron is added to a neutral atom, a certain amount of energy is
a. either released or absorbed. b. transferred to the more electronegative element. c. always absorbed. d. always
released.
31. The measure of an atom’s ability to attract electrons is its
a. ionization b. polarization. c. electron affinity d. electronegativity
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Name: ________________________
ID: A
32. Valence electrons are those s and p electrons
a. combined with protons. b. in the highest energy level. c. closest to the nucleus. d. in the lowest energy level.
33. According to VSEPR theory, which molecule has a bent shape?
a. CS2 b. HF c. CO2 d. H2O
34. The electrons available to be lost, gained, or shared when atoms form compounds are called
a. electron clouds. b. ions. c. valence electrons. d. d electrons.
35. The chemical formula of an ionic compound shows
a. how many atoms of each element a molecule contains. b. which molecules the ionic compound contains. c. how the atoms bond. d. the lowest whole-number ratio between ions in the ionic compound.
36. One-half the distance between the nuclei of identical atoms that are bonded together is called the
a. atomic diameter. b. atomic volume. c. atomic radius. d. electron cloud.
37. The structure of which of the following compounds suggests that it has the highest boiling point?
a. O2 b. CO2 c. CH4 d. NaCl
38. Which of the following statements is true about ions?
a. Charges for ions are always written as numbers followed by a plus or minus sign. b. Cations are common among nonmetals. c. When an anion forms, more electrons are transferred to it. d. Anions are positively charged ions.
39. The crystal structure of an ionic compound depends on the
a. ratio of cations to anions. b. sizes of the cations and anions. c. masses of the cation and anion. d. Both (a) and (b)
40. The energy required to remove an electron from an atom is the atom's
a. ionization energy. b. electron affinity. c. electron energy. d. electronegativity.
41. Under what conditions can potassium bromide conduct electricity?
a. only when it is in crystal form b. only when melted c. only when melted or dissolved in water d. only when dissolved
42. VSEPR theory is a model for predicting
a. the shape of molecules. b. the strength of metallic bonds. c. lattice energy values. d. ionization energy.
43. The greater the electronegativity difference between two bonded atoms, the greater the percentage of ____ in the bond.
a. ionic character b. electron sharing c. metallic character d. covalent character
44. The energy released when 1 mol of an ionic crystalline compound is formed from gaseous ions is called the
a. lattice energy. b. potential energy. c. energy of crystallization. d. bond energy.
45. In Group 2 elements, the valence electrons are in sublevel
a. s. b. p. c. f. d. d.
46. Ionic compounds are brittle because the strong attractive forces
a. cause the compound to vaporize easily. b. allow the layers to shift easily. c. hold the layers in relatively fixed
positions. d. keep the surface dull.
47. In a row in the periodic table, as the atomic number increases, the atomic radius generally
a. becomes immeasurable. b. decreases. c. remains constant. d. increases.
48. Most chemical bonds are
a. metallic. b. purely ionic. c. partly ionic and partly covalent. d. purely covalent.
49. What causes water molecules to have a bent shape, according to VSEPR theory?
a. interaction between the fixed orbitals of the unshared pairs of oxygen b. repulsive forces between unshared pairs of electrons c. ionic attraction and repulsion d. the unusual location of the free electrons
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Name: ________________________
ID: A
50. Resonance structures differ by __________.
a. placement of electrons only b. placement of atoms only c. number and placement of electrons d. number of atoms only
51. Bond length is the distance between two bonded atoms at
a. one-half the diameter of the electron cloud. b. their maximum kinetic energy. c. their maximum potential energy.
d. their minimum potential energy.
52. Ionic compounds are normally in which physical state at room temperature?
a. solid b. gas c. plasma d. liquid
53.
The molecule described by the figure above has an average bond length of
a. 70 kJ/mol. b. 290 pm. c. 347 kJ/mol. d. 154 pm.
54. In a double covalent bond,
a. one atom has more than eight valence electrons. b. two atoms share eight valence electrons. c. one atom loses a pair
of electrons. d. two atoms share two pairs of electrons.
55. What is placed between a molecule's resonance structures to indicate resonance?
a. series of dots b. double-headed arrow c. Lewis structure d. single-headed arrow
56. Which represents a neutral atom acquiring an electron in a process where energy is released?
a. A + e–  A– – energy b. A– + energy  A + e– c. A + e– + energy  A– d. A + e–  A– + energy
57. In drawing a Lewis structure, the central atom is generally the
a. atom with the greatest mass. b. least electronegative atom. c. atom with the fewest electrons. d. atom with the
highest atomic number.
58. How many extra electrons are in the Lewis structure of the phosphate ion, PO43–?
a. 2 b. 0 c. 3 d. 4
59. Which elements can form diatomic molecules joined by a single covalent bond?
a. halogens only b. hydrogen only c. halogens and members of the oxygen group only d. hydrogen and the halogens only
60. A resonance structure, like the one above, represents
a. a difference in bond length, one shorter than the other. b. a difference in energy. c. a hybrid of the extremes
represented by the resonance forms. d. electron pairs resonating back and forth between the extremes of the two structures.
61. According to VSEPR theory, if there are four electron domains on a central atom, they will be arranged such that the angles
between the domains are __________.
a. 109.5° b. 120° c. 360° d. 90°
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