Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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The electrons involved in the formation of a chemical bond are called
a. | dipoles. | c. | Lewis electrons. | b. | s electrons. | d. | valence
electrons. |
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2.
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The electrostatic attraction between positively charged nuclei and negatively
charged electrons permits two atoms to be held together by a(n)
a. | chemical bond. | c. | neutron. | b. | London force. | d. | ion. |
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3.
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As independent particles, most atoms are
a. | at relatively high potential energy. | c. | very stable. | b. | at relatively low
potential energy. | d. | part of a
chemical bond. |
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4.
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Atoms naturally move
a. | toward high potential energy. | c. | toward less
stability. | b. | toward low potential energy. | d. | away from each
other. |
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5.
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When atoms share electrons, the electrical attraction of an atom for the shared
electrons is called the atom's
a. | electron affinity. | c. | resonance. | b. | electronegativity. | d. | hybridization. |
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6.
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If the atoms that share electrons have an unequal attraction for the electrons,
the bond is called
a. | nonpolar. | c. | ionic. | b. | polar. | d. | dipolar. |
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7.
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What are shared in a covalent bond?
a. | ions | c. | electrons | b. | Lewis structures | d. | dipoles |
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8.
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Most chemical bonds are
a. | purely ionic. | c. | partly ionic and partly covalent. | b. | purely
covalent. | d. | metallic. |
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9.
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Nonpolar covalent bonds are not common because
a. | one atom usually attracts electrons more strongly than the other. | b. | ions always form
when atoms join. | c. | the electrons usually remain equally distant from both atoms. | d. | dipoles are rare in
nature. |
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10.
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The pair of elements that forms a bond with the least ionic character is
a. | Na and Cl. | c. | O and Cl. | b. | K and Cl. | d. | Mg and Cl. |
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11.
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In the three molecules, O2, HCl, and F2, what atom would
have a partial negative charge?
a. | oxygen | c. | chlorine | b. | hydrogen | d. | fluorine |
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12.
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The percentage ionic character and the type of bond in Br2
(electronegativity for Br is 2.8) is
a. | 0%; nonpolar covalent. | c. | 0%; pure ionic. | b. | 100%; polar covalent. | d. | 100%; pure
ionic. |
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13.
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A neutral group of atoms held together by covalent bonds is a
a. | molecular formula. | c. | polyatomic ion. | b. | chemical formula. | d. | molecule. |
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14.
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Which of the following shows the types and numbers of atoms joined in a single
molecule of a molecular compound?
a. | molecular formula | c. | covalent bond | b. | potential energy diagram | d. | ionic bond |
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15.
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Bond length is the average distance between two bonded atoms
a. | at which potential energy is at a minimum. | b. | at which kinetic
energy is at a maximum. | c. | at which potential energy is at a
maximum. | d. | and equal to one-half the diameter of the electron
cloud. |
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16.
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The energy released when a covalent bond forms is the difference between zero
and the
a. | maximum potential energy. | c. | minimum potential
energy. | b. | kinetic energy of the atom. | d. | bond length expressed in nanometers. |
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17.
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In a molecule of fluorine, the two shared electrons give each fluorine atom how
many electron(s) in the outer energy level?
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18.
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What group of elements satisfies the octet rule without forming
compounds?
a. | halogen | c. | alkali metal | b. | noble gas | d. | alkaline-earth
metal |
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19.
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In drawing a Lewis structure, the central atom is generally the
a. | atom with the greatest mass. | b. | atom with the highest atomic
number. | c. | atom with the fewest electrons. | d. | least electronegative
atom. |
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20.
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To draw a Lewis structure, one must know the
a. | number of valence electrons in each atom. | b. | atomic mass of each
atom. | c. | bond length of each atom. | d. | ionization energy of each
atom. |
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21.
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What is the correct Lewis structure for hydrogen chloride, HCl?  
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22.
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Bonding in molecules or ions that cannot be correctly represented by a single
Lewis structure is
a. | polyatomic. | c. | single bonding. | b. | resonance. | d. | double bonding. |
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23.
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What is placed between a molecule's resonance structures to indicate
resonance?
a. | double-headed arrow | c. | series of dots | b. | single-headed arrow | d. | Lewis structure |
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24.
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A formula that shows only the types and numbers of atoms combined in a single
molecule is called a(n)
a. | molecular formula. | c. | Lewis structure. | b. | ionic formula. | d. | covalent
formula. |
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25.
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In the NaCl crystal, each Na+ and Cl– ion has how
many oppositely charged ions clustered around it?
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26.
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In a crystal, the electrons of adjacent ions
a. | repel each other. | c. | neutralize each other. | b. | attract each
other. | d. | have no effect on
each other. |
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27.
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If the lattice energy of compound A is greater than that of compound B,
a. | compound A is not an ionic compound. | b. | the bonds in compound A are stronger than the
bonds in compound B. | c. | compound B is probably a
gas. | d. | compound A has larger crystals than compound B. |
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28.
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The forces of attraction between molecules in a molecular compound are
a. | stronger than the forces among formula units in ionic bonding. | b. | weaker than the
forces among formula units in ionic bonding. | c. | approximately equal to the forces among formula
units in ionic bonding. | d. | zero. |
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29.
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The Lewis structure for the ammonium ion, NH4, has
a. | nonpolar covalent bond. | c. | polar covalent
bond. | b. | ionic bond. | d. | metallic bond. |
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30.
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How many electrons must be shown in the Lewis structure of the hydroxide ion,
OH–?
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31.
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A chemical bond formed by the attraction between positive ions and surrounding
mobile electrons is a(n)
a. | nonpolar covalent bond. | c. | polar covalent
bond. | b. | ionic bond. | d. | metallic bond. |
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32.
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Compared with nonmetals, the number of valence electrons in metals is
generally
a. | smaller. | c. | about the same. | b. | greater. | d. | almost triple. |
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33.
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In metals, the valence electrons
a. | are attached to particular positive ions. | c. | are immobile. | b. | are shared by all of
the atoms. | d. | form covalent
bonds. |
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34.
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To appear shiny, a material must be able to
a. | form crystals. | b. | absorb and re-emit light of many
wavelengths. | c. | absorb light and change it all to energy as heat. | d. | change light to
electricity. |
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35.
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The shiny appearance of a metal is most closely related to the
metal's
a. | highly mobile valence electrons. | c. | brittle crystalline
structure. | b. | covalent bonds. | d. | positive ions. |
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36.
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Which best explains the observation that metals are malleable and ionic crystals
are brittle?
a. | their chemical bonds | c. | their enthalpies of vaporization | b. | their London
forces | d. | their net
change |
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37.
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Malleability and ductility are characteristic of substances with
a. | covalent bonds. | c. | Lewis structures. | b. | ionic bonds. | d. | metallic bonds. |
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38.
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According to VSEPR theory, an AB2 molecule is
a. | trigonal-planar. | c. | linear. | b. | tetrahedral. | d. | octahedral. |
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39.
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The concept that electrostatic repulsion between electron pairs surrounding an
atom causes these pairs to be separated as far as possible is the foundation of
a. | VSEPR theory. | c. | the electron-sea model. | b. | the hybridization
model. | d. | Lewis
theory. |
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40.
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According to VSEPR theory, the shape of an AB3 molecule is
a. | trigonal-planar. | c. | linear. | b. | tetrahedral. | d. | bent. |
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41.
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Use VSEPR theory to predict the shape of the hydrogen chloride molecule,
HCl.
a. | tetrahedral | c. | bent | b. | linear | d. | trigonal-planar |
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42.
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Use VSEPR theory to predict the shape of the magnesium hydride molecule,
MgH2.
a. | tetrahedral | c. | bent | b. | linear | d. | octahedral |
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43.
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Use VSEPR theory to predict the shape of the chlorate ion,
ClO3–.
a. | trigonal-planar | c. | trigonal-pyramidal | b. | octahedral | d. | bent |
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44.
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Use VSEPR theory to predict the shape of carbon dioxide, CO2.
a. | tetrahedral | c. | bent | b. | linear | d. | octahedral |
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45.
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Dipole-dipole forces are considered the most important forces in polar
substances because the London dispersion forces present in polar substances
a. | are no longer present. | b. | are usually much weaker than the dipole-dipole
forces. | c. | are too unpredictable. | d. | act only in
solids. |
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46.
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The strength of London dispersion forces between molecules depends on
a. | only the number of electrons in the molecule. | b. | only the number of
protons in the molecule. | c. | both the number of electrons in the molecule
and the mass of the molecule. | d. | both the number of electrons and the number of
neutrons in the molecule. |
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47.
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The strong forces of attraction between the positive and negative regions of
molecules are called
a. | dipole-dipole forces. | c. | lattice forces. | b. | London forces. | d. | orbital forces. |
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48.
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The equal but opposite charges present in the two regions of a polar molecule
create a(n)
a. | electron sea. | c. | crystal lattice. | b. | dipole. | d. | ionic bond. |
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49.
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A polar molecule contains
a. | ions. | b. | a region of positive charge and a region of
negative charge. | c. | only London forces. | d. | no bonds. |
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50.
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Iodine monochloride (ICl) has a higher boiling point than bromine
(Br2) partly because iodine monochloride is a(n)
a. | nonpolar molecule. | c. | metal. | b. | polyatomic ion. | d. | polar molecule. |
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