Chemistry terms

Joshua F. (United States of America)
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  1. Coulomb's Law
    a fundamental principle of electrostatics
    Ions paired have lower energy (greater stability) than separated ions
    B. Coulomb's Law
    1.
    ø
    ö
    è
    æ
    = ×
    -
    r
    Q Q
    E x J nm
    19 1 2
    2.31 10
    a.
  2. valence electron
    an electron in the outer shell of an atom which can combine with other atoms to form molecules
    Valence electron arrangement using Lewis structures
    2.
  3. enthalpy
    (thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure
    As the number of shared electrons increases, the bond length shortens
    (see table 8.5)
    C. Bond Energy and Enthalpy (using bond energy to calculate approximate
    energies for rxns)
    1.
  4. covalent
    of or relating to or characterized by covalence
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  5. dipole moment
    the moment of a dipole
    Molecules with a somewhat negative end and a somewhat positive end
    (a dipole moment)
    2.
  6. electronegativity
    (chemistry) the tendency of an atom or radical to attract electrons in the formation of an ionic bond
    Atoms end up with fractional charges
    (1) d+ or d-
    8.2 Electronegativity
    A. Electronegativity
    1.
  7. covalent bond
    a chemical bond that involves sharing a pair of electrons between atoms in a molecule
    All diatomic molecules with a polar covalent bond are dipolar
    B. Molecules with Polar Bonds but no Dipole Moment
    1.
  8. sulfur hexafluoride
    a colorless gas that is soluble in alcohol and ether
    Boron often forms molecules that obey the octet
    rule
    B. Sulfur Hexafluoride
    1.
  9. ionic charge
    the charge on an ion is equal to a constant charge e multiplied by an integer from 1 to 15
    Formulas for compounds are balanced so that the total positive ionic
    charge is equal to the total negative ionic charge
    Al O
    2
    3
    3
    2
    + -
    Total positive = +6
    Total negative = -6
    C. Sizes of Ions
    1.
  10. noble gas
    any of the chemically inert gaseous elements of the helium group in the periodic table
    See table 8.2 in your text
    8.4 Ions: Electron Configurations and Sizes
    A. Bonding and Noble Gas Electron Configurations
    1.
  11. dipole
    an aerial half a wavelength long consisting of two rods connected to a transmission line at the center
    Bond Polarity and Dipole Moments
    A. Dipolar Molecules
    1.
  12. dipolar
    having equal and opposite electric charges or magnetic poles having opposite signs and separated by a small distance
    Bond Polarity and Dipole Moments
    A. Dipolar Molecules
    1.
  13. nonequivalent
    not equal or interchangeable in value, quantity, or significance
    If nonequivalent Lewis structures exist for a species, those with the
    formal charges closest to zero, and with negative formal charges on
    the most electronegative atoms are considered the best candidates
    2.
  14. ionic
    containing or involving electrically charged particles
    Greater electronegativity difference between two elements means less
    covalent character and greater ionic character
    2.
  15. octet
    eight performers or singers who perform together
    Octet Rule
    a.
  16. electron
    an elementary particle with negative charge
    Electrons are transferred
    2.
  17. trigonal
    having threefold symmetry
    Non-bonding and bonding electron pairs will be as far apart as possible
    Arrangement of Electron Pairs Around an Atom Yielding Minimum
    Repulsion
    # of Electron
    Pairs
    Shape Arrangement of Electron Pairs
    2 Linear

    3 Trigonal Planar
    4 Tetrahedral
    5 Trigonal bipyramidal

    6 Octahedral
    B. Effect of Unshared Electron Pairs
    1.
  18. chemical bond
    an electrical force linking atoms
    AP Chemistry
    A. Allan
    Chapter 8 Notes - Bonding: General Concepts
    8.1 Types of Chemical Bonds
    A. Ionic Bonding
    1.
  19. boron trifluoride
    a pungent colorless gas
    Arrange the remaining atoms to satisfy the duet rule for
    hydrogen and the octet rule for the second row elements
    8.11 Exceptions to the Octet Rule
    A. Boron Trifluoride
    1.
  20. exothermic
    occurring or formed with the release of heat
    Energy change is exothermic (negative sign)
    Example: Formation of lithium fluoride
    Process Description Energy Change (kJ)
    Li(s) ‡ Li(g) Sublimation energy 161
    Li(g) ‡ Li
    +
    (g) + e
    -
    Ionization energy 520
    1/2F2 ‡ F(g) Bond energy (1/2 mole) 77
    F(g) + e
    -
    ‡ F
    -
    (g) Electron affinity -328
    Li
    +
    (g) + F
    -
    (g) ‡ LiF(s) Lattice energy -1047
    Li(s) + 1/2F2(g) ‡ LiF(s) DH -617
    3.
  21. electronegative
    having a negative charge
    If nonequivalent Lewis structures exist for a species, those with the
    formal charges closest to zero, and with negative formal charges on
    the most electronegative atoms are considered the best candidates
    2.
  22. polyatomic
    of or relating to a molecule made up of more than two atoms
    Percent ionic character is difficult to calculate for compounds
    containing polyatomic ions8.7 The Covalent Chemical Bond: A Model
    A. Strengths of the Bond Model
    1.
  23. joule
    a unit of electrical energy
    E = energy in joules
    b.
  24. nonmetal
    not resembling shiny, malleable, conductive elements
    Metals react with nonmetals
    3.
  25. endothermic
    occurring or formed with absorption of heat
    The formation of ionic compounds is endothermic until the formation of
    the lattice
    4.
  26. rotatable
    capable of being rotated
    Look at real 3-dimensional, rotatable models to develop predictive
    skills
    E. How Well Does VSEPR Work?
  27. 3-dimensional
    involving or relating to three dimensions or aspects
    Look at real 3-dimensional, rotatable models to develop predictive
    skills
    E. How Well Does VSEPR Work?
  28. alkali metal
    any of the monovalent metals of group I of the periodic table (lithium or sodium or potassium or rubidium or cesium or francium)
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  29. localize
    concentrate on a particular place or spot
    D always has a positive sign8.9 The Localized Electron Bonding Model
    A. Lone electron pairs
    1.
  30. nanometer
    a metric unit of length equal to one billionth of a meter
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  31. diatomic
    of or relating to a molecule made up of two atoms
    All diatomic molecules with a polar covalent bond are dipolar
    B. Molecules with Polar Bonds but no Dipole Moment
    1.
  32. bonding
    the act of fastening firmly together
    AP Chemistry
    A. Allan
    Chapter 8 Notes - Bonding: General Concepts
    8.1 Types of Chemical Bonds
    A. Ionic Bonding
    1.
  33. planar
    involving two dimensions
    Non-bonding and bonding electron pairs will be as far apart as possible
    Arrangement of Electron Pairs Around an Atom Yielding Minimum
    Repulsion
    # of Electron
    Pairs
    Shape Arrangement of Electron Pairs
    2 Linear

    3 Trigonal Planar
    4 Tetrahedral
    5 Trigonal bipyramidal

    6 Octahedral
    B. Effect of Unshared Electron Pairs
    1.
  34. unshared
    not shared
    Electrons localized on an atom (unshared)
    B. Bonding electron pairs
    1.
  35. cation
    a particle with a positive electric charge
    Cations are smaller than the parent atom
    3.
  36. double bond
    a covalent bond in which two pairs of electrons are shared between two atoms
    Double bonds - 2 pairs of shared electrons
    3.
  37. anion
    a particle with a negative electric charge
    Anions are larger than the parent atom
    2.
  38. molecule
    the simplest structural unit of an element or compound
    The ability of an atom in a molecule to attract shared electrons to itself
    B. Electronegativity Trends
    1.
  39. pack together
    make more compact by or as if by pressing
    The change in energy that takes place when separated gaseous ions
    are packed together to form an ionic solid
    M
    +
    (g) + X
    -
    (g) ‡ MX (s)
    2.
  40. repulsive force
    the force by which bodies repel one another
    Repulsive forces (electron - electron, proton - proton)
    3.
  41. Ionic
    of or relating to Ionia or its inhabitants or its language
    AP Chemistry
    A. Allan
    Chapter 8 Notes - Bonding: General Concepts
    8.1 Types of Chemical Bonds
    A. Ionic Bonding
    1.
  42. boron
    a trivalent metalloid element
    Hydrogen, lithium, beryllium, and boron form stable molecules
    when they share two electrons (helium configuration)
    3.
  43. ion
    a particle that is electrically charged positive or negative
    Ions paired have lower energy (greater stability) than separated ions
    B. Coulomb's Law
    1.
    ø
    ö
    è
    æ
    = ×
    -
    r
    Q Q
    E x J nm
    19 1 2
    2.31 10
    a.
  44. valence
    the capacity of something or someone to react with or affect others
    Electrons are shared in order to complete the valence
    configurations of both atoms
    B. Predicting Formulas of Ionic Compounds
    1.
  45. Bond
    United States civil rights leader who was elected to the legislature in Georgia but was barred from taking his seat because he opposed the Vietnam War (born 1940)
    AP Chemistry
    A. Allan
    Chapter 8 Notes - Bonding: General Concepts
    8.1 Types of Chemical Bonds
    A. Ionic Bonding
    1.
  46. proton
    a stable particle with positive charge
    Attractive forces (proton - electron)
    b.
  47. atom
    the smallest component of an element
    Energy is given off (bond energy) when two atoms achieve greater
    stability together than apart
    D. Covalent Bonds
    1.
  48. acceptor
    the person (or institution) who accepts a check or draft and becomes responsible for paying the party named in the draft when it matures
    BF3 is electron deficient and acts as a Lewis acid
    (electron pair acceptor)
    3.
  49. configuration
    an arrangement of parts or elements
    See table 8.2 in your text
    8.4 Ions: Electron Configurations and Sizes
    A. Bonding and Noble Gas Electron Configurations
    1.
  50. attractive force
    the force by which one object attracts another
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  51. cesium
    a soft silver-white ductile metallic element
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  52. localized
    confined or restricted to a particular place
    D always has a positive sign8.9 The Localized Electron Bonding Model
    A. Lone electron pairs
    1.
  53. resonance
    the characteristic of having a loud deep sound
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  54. periodic table
    arrangement of chemical elements according to atomic number
    Placement of elements on the periodic table suggests how many
    electrons are lost or gained to achieve a noble-gas configuration
    a.
  55. halogen
    any of five related nonmetallic elements (fluorine or chlorine or bromine or iodine or astatine) that are all monovalent and readily form negative ions
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  56. bond
    a connection that fastens things together
    AP Chemistry
    A. Allan
    Chapter 8 Notes - Bonding: General Concepts
    8.1 Types of Chemical Bonds
    A. Ionic Bonding
    1.
  57. proportionality
    harmonious arrangement or relation of parts or elements within a whole (as in a design)
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  58. lattice
    an arrangement of points in a regular periodic pattern
    Size decreases as the nuclear charge Z increases8.5 Formation of Binary Ionic Compounds
    A. Lattice Energy
    1.
  59. beryllium
    a light strong brittle grey toxic bivalent metallic element
    Hydrogen, lithium, beryllium, and boron form stable molecules
    when they share two electrons (helium configuration)
    3.
  60. ionization
    the process of ionizing
    Energy change is exothermic (negative sign)
    Example: Formation of lithium fluoride
    Process Description Energy Change (kJ)
    Li(s) ‡ Li(g) Sublimation energy 161
    Li(g) ‡ Li
    +
    (g) + e
    -
    Ionization energy 520
    1/2F2 ‡ F(g) Bond energy (1/2 mole) 77
    F(g) + e
    -
    ‡ F
    -
    (g) Electron affinity -328
    Li
    +
    (g) + F
    -
    (g) ‡ LiF(s) Lattice energy -1047
    Li(s) + 1/2F2(g) ‡ LiF(s) DH -617
    3.
  61. electric field
    a field of force surrounding a charged particle
    Molecules with preferential orientation in an electric field
    + + +
    - - -
    3.
  62. sulfur
    an abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions)
    Boron often forms molecules that obey the octet
    rule
    B. Sulfur Hexafluoride
    1.
  63. chemical reaction
    a process in which substances are changed into others
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  64. lithium
    a soft silver-white univalent element of the alkali metal group; the lightest metal known; occurs in several minerals
    Energy change is exothermic (negative sign)
    Example: Formation of lithium fluoride
    Process Description Energy Change (kJ)
    Li(s) ‡ Li(g) Sublimation energy 161
    Li(g) ‡ Li
    +
    (g) + e
    -
    Ionization energy 520
    1/2F2 ‡ F(g) Bond energy (1/2 mole) 77
    F(g) + e
    -
    ‡ F
    -
    (g) Electron affinity -328
    Li
    +
    (g) + F
    -
    (g) ‡ LiF(s) Lattice energy -1047
    Li(s) + 1/2F2(g) ‡ LiF(s) DH -617
    3.
  65. dimensional
    relating to coordinates that determine a position in space
    Look at real 3-dimensional, rotatable models to develop predictive
    skills
    E. How Well Does VSEPR Work?
  66. physical structure
    the entire structure of an organism
    Bonds are not actual physical structures
    2.
  67. predictive
    relating to prediction
    Look at real 3-dimensional, rotatable models to develop predictive
    skills
    E. How Well Does VSEPR Work?
  68. Energy
    the federal department responsible for maintaining a national energy policy of the United States; created in 1977
    Energy is given off (bond energy) when two atoms achieve greater
    stability together than apart
    D. Covalent Bonds
    1.
  69. repulsion
    the act of successfully defending against an attack
    Prediction of molecular geometry using VSEPR (valence shell electron
    pair repulsion)
    3.
  70. compound
    a whole formed by a union of two or more elements or parts
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  71. mol
    the molecular weight of a substance expressed in grams
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  72. reactive
    participating in processes changing substances into others
    B and Be (second row) often have fewer then eight electrons around
    them, and form electron deficient, highly reactive molecules
    3.
  73. sublimation
    a change directly from the solid to the gaseous state
    Energy change is exothermic (negative sign)
    Example: Formation of lithium fluoride
    Process Description Energy Change (kJ)
    Li(s) ‡ Li(g) Sublimation energy 161
    Li(g) ‡ Li
    +
    (g) + e
    -
    Ionization energy 520
    1/2F2 ‡ F(g) Bond energy (1/2 mole) 77
    F(g) + e
    -
    ‡ F
    -
    (g) Electron affinity -328
    Li
    +
    (g) + F
    -
    (g) ‡ LiF(s) Lattice energy -1047
    Li(s) + 1/2F2(g) ‡ LiF(s) DH -617
    3.
  74. linear
    involving a single dimension
    Linear, radial or tetrahedral symmetry of charge distribution
    a.
  75. fluoride
    a chemical used to help prevent tooth decay
    Energy change is exothermic (negative sign)
    Example: Formation of lithium fluoride
    Process Description Energy Change (kJ)
    Li(s) ‡ Li(g) Sublimation energy 161
    Li(g) ‡ Li
    +
    (g) + e
    -
    Ionization energy 520
    1/2F2 ‡ F(g) Bond energy (1/2 mole) 77
    F(g) + e
    -
    ‡ F
    -
    (g) Electron affinity -328
    Li
    +
    (g) + F
    -
    (g) ‡ LiF(s) Lattice energy -1047
    Li(s) + 1/2F2(g) ‡ LiF(s) DH -617
    3.
  76. Angle
    a member of a Germanic people who conquered England and merged with the Saxons and Jutes to become Anglo-Saxons
    The ideal tetrahedral angle is 109.5°
    Comparison of Tetrahedral Bond Angles
    Compound Structure Angle between
    Hydrogens
    Methane

    109.5°
    Ammonia 107°
    Water 104.5°
    2.
  77. give off
    have as a by-product
    Energy is given off (bond energy) when two atoms achieve greater
    stability together than apart
    D. Covalent Bonds
    1.
  78. structure
    a complex entity made of many parts
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  79. pair
    a set of two similar things considered as a unit
    Ions paired have lower energy (greater stability) than separated ions
    B. Coulomb's Law
    1.
    ø
    ö
    è
    æ
    = ×
    -
    r
    Q Q
    E x J nm
    19 1 2
    2.31 10
    a.
  80. molecular
    relating to the simplest units of an element or compound
    Prediction of molecular geometry using VSEPR (valence shell electron
    pair repulsion)
    3.
  81. subtraction
    arithmetic operation of deducting one quantity from another
    We will not use the subtraction of electronegativities to determine ionic
    character.
  82. polarity
    a relation between two opposite attributes or tendencies
    Bond Polarity and Dipole Moments
    A. Dipolar Molecules
    1.
  83. shared
    have in common; held or experienced in common
    Electrons are shared by nuclei
    2.
  84. spatial
    pertaining to the expanse in which things are located
    Allows the drawing of structures showing the spatial relationship
    between atoms in a molecule
    3.
  85. calculate
    make a mathematical computation
    Lattice energy increases as the ionic charge increases and the
    distance between anions and cations decreases
    8.6 Partial Ionic Character of Covalent Bonds
    A. Calculating Percent Ionic Character
    x100%
    calculated dipole moment of X Y
    measured dipole moment of X Y
    Percent ionic character
    ø
    ö
    è
    æ -
    =
    + -
    B. Ionic vs.
  86. preferential
    showing favor or partiality
    Molecules with preferential orientation in an electric field
    + + +
    - - -
    3.
  87. nitrate
    any compound containing the nitrate group
    When necessary to exceed the octet rule for one of several third
    row elements, assume that the extra electrons be placed on the
    central atom
    8.12 Resonance
    A. Nitrate ion
    1.
  88. fractional
    constituting or comprising a part or fraction of a possible whole or entirety
    Atoms end up with fractional charges
    (1) d+ or d-
    8.2 Electronegativity
    A. Electronegativity
    1.
  89. duet
    two performers or singers who perform together
    Duet rule
    a.
  90. unequally
    in an unequal or partial manner
    Electrons are shared unequally
    b.
  91. polar
    of or existing within the Arctic or Antarctic Circles
    Pure covalent (non-polar covalent)
    a.
  92. energy
    forceful exertion
    Ions paired have lower energy (greater stability) than separated ions
    B. Coulomb's Law
    1.
    ø
    ö
    è
    æ
    = ×
    -
    r
    Q Q
    E x J nm
    19 1 2
    2.31 10
    a.
  93. orbital
    relating to the path of one body around another
    SF6 fills the 3s and 3p orbitals with 8 of the
    valence electrons, and places the other 4 in the
    higher energy 3d orbital
    C. More About the Octet Rule
    1.
  94. radial
    relating to or near the radius
    Linear, radial or tetrahedral symmetry of charge distribution
    a.
  95. lone
    being the only one; single and isolated from others
    D always has a positive sign8.9 The Localized Electron Bonding Model
    A. Lone electron pairs
    1.
  96. CO2
    a colorless, odorless greenhouse gas essential for photosynthesis
    CO2 - linear
    b.
  97. methane
    a colorless, odorless gas used as a fuel
    The ideal tetrahedral angle is 109.5°
    Comparison of Tetrahedral Bond Angles
    Compound Structure Angle between
    Hydrogens
    Methane

    109.5°
    Ammonia 107°
    Water 104.5°
    2.
  98. model
    a representation of something, often on a smaller scale
    Percent ionic character is difficult to calculate for compounds
    containing polyatomic ions8.7 The Covalent Chemical Bond: A Model
    A. Strengths of the Bond Model
    1.
  99. compress
    squeeze or push together
    Lone (unshared) electron pairs require more room than bonding pairs
    (they have greater repulsive forces) and tend to compress the angles
    between bonding pairs
    3.
  100. element
    a substance that cannot be separated into simpler substances
    Greater electronegativity difference between two elements means less
    covalent character and greater ionic character
    2.
  101. decrease
    a change downward
    Electronegativity generally decrease within a family (why?)
  102. multiple
    having or involving more than one part or entity
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  103. hydrogen
    a colorless, odorless gas; the lightest chemical element
    Hydrogen, lithium, beryllium, and boron form stable molecules
    when they share two electrons (helium configuration)
    3.
  104. electric current
    a flow of electricity through a conductor
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  105. Lewis
    English critic and novelist
    Valence electron arrangement using Lewis structures
    2.
  106. binary
    of or pertaining to a number system having 2 as its base
    Size decreases as the nuclear charge Z increases8.5 Formation of Binary Ionic Compounds
    A. Lattice Energy
    1.
  107. elements
    violent or severe weather
    Greater electronegativity difference between two elements means less
    covalent character and greater ionic character
    2.
  108. negative
    characterized by denial or opposition or resistance
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  109. add up
    add up in number or quantity
    Add up the TOTAL number of valence electrons from all atoms
    b.
  110. placement
    the spatial property of the way in which something is placed
    Placement of elements on the periodic table suggests how many
    electrons are lost or gained to achieve a noble-gas configuration
    a.
  111. orientation
    the act of determining one's position
    Molecules with preferential orientation in an electric field
    + + +
    - - -
    3.
  112. gaseous
    existing as or having the qualities of a gas
    The change in energy that takes place when separated gaseous ions
    are packed together to form an ionic solid
    M
    +
    (g) + X
    -
    (g) ‡ MX (s)
    2.
  113. helium
    a light colorless element that is one of the six inert gases
    Hydrogen, lithium, beryllium, and boron form stable molecules
    when they share two electrons (helium configuration)
    3.
  114. evaluate
    estimate the nature, quality, ability or significance of
    If the charge on an ion is -2, the sum of the formal charges must
    be -2
    E. Using Formal Charge to Evaluate Lewis Structures
    1.
  115. formation
    the act of establishing or creating something
    Size decreases as the nuclear charge Z increases8.5 Formation of Binary Ionic Compounds
    A. Lattice Energy
    1.
  116. distortion
    a shape resulting from being deformed
    Lone pairs do not cause distortion when bond angles are 120° or
    greater
    C. VSEPR and Multiple Bonds
    1.
  117. minimize
    make small or insignificant
    The structure around a given atom is determined principally by
    minimizing electron-pair repulsions
    2.
  118. repulsive
    offensive to the mind or senses
    Repulsive forces (electron - electron, proton - proton)
    3.
  119. paired
    used of gloves, socks, etc.
    Ions paired have lower energy (greater stability) than separated ions
    B. Coulomb's Law
    1.
    ø
    ö
    è
    æ
    = ×
    -
    r
    Q Q
    E x J nm
    19 1 2
    2.31 10
    a.
  120. share
    assets belonging to an individual person or group
    Electrons are shared by nuclei
    2.
  121. formal
    in accord with established conventions and requirements
    Does not fit localized electron model
    D. Formal Charge
    1.
  122. charge
    assign a duty, responsibility or obligation to
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  123. rule
    prescribed guide for conduct or action
    Duet rule
    a.
  124. exceed
    be or do something to a greater degree
    Second row elements never exceed the octet rule
    4.
  125. mole
    a small congenital pigmented spot on the skin
    Energy change is exothermic (negative sign)
    Example: Formation of lithium fluoride
    Process Description Energy Change (kJ)
    Li(s) ‡ Li(g) Sublimation energy 161
    Li(g) ‡ Li
    +
    (g) + e
    -
    Ionization energy 520
    1/2F2 ‡ F(g) Bond energy (1/2 mole) 77
    F(g) + e
    -
    ‡ F
    -
    (g) Electron affinity -328
    Li
    +
    (g) + F
    -
    (g) ‡ LiF(s) Lattice energy -1047
    Li(s) + 1/2F2(g) ‡ LiF(s) DH -617
    3.
  126. stability
    the quality or attribute of being firm and steadfast
    Ions paired have lower energy (greater stability) than separated ions
    B. Coulomb's Law
    1.
    ø
    ö
    è
    æ
    = ×
    -
    r
    Q Q
    E x J nm
    19 1 2
    2.31 10
    a.
  127. alkali
    any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  128. predict
    make a guess about what will happen in the future
    Electrons are shared in order to complete the valence
    configurations of both atoms
    B. Predicting Formulas of Ionic Compounds
    1.
  129. depict
    give a description of
    The actual structure is an average of the depicted resonance
    structures
    C. Odd Electron Molecules
    1.
  130. deficient
    inadequate in amount or degree
    BF3 is electron deficient and acts as a Lewis acid
    (electron pair acceptor)
    3.
  131. variant
    something a little different from others of the same type
    A resonance structure is drawn by writing the three
    variant structures, connected by a double-headed
    arrow
    B. Resonance
    1.
  132. characterize
    be typical of
    C. Characterizing bonds
    1.
  133. derivation
    the source or origin from which something comes
    "A molecule is composed of atoms that are bound together by sharing
    pairs of electrons using the atomic orbitals of the bound atoms
    D. Derivations of the Localized Model
    1.
  134. angle
    the space between two lines or planes that intersect
    The ideal tetrahedral angle is 109.5°
    Comparison of Tetrahedral Bond Angles
    Compound Structure Angle between
    Hydrogens
    Methane

    109.5°
    Ammonia 107°
    Water 104.5°
    2.
  135. conclusively
    in a conclusive way
    Only experimental evidence can conclusively determine the correct
    bonding situation in a molecule
    8.13 Molecular Structure: The VSEPR Model
    A. Valence Shell Electron Pair Repulsion (VSEPR)
    1.
  136. chemical
    produced by reactions involving atomic or molecular changes
    AP Chemistry
    A. Allan
    Chapter 8 Notes - Bonding: General Concepts
    8.1 Types of Chemical Bonds
    A. Ionic Bonding
    1.
  137. numerical
    of or relating to or denoting numerals
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  138. achieve
    gain with effort
    Energy is given off (bond energy) when two atoms achieve greater
    stability together than apart
    D. Covalent Bonds
    1.
  139. non
    negation of a word or group of words
    Pure covalent (non-polar covalent)
    a.
  140. stable
    resistant to change of position or condition
    Description of the type of atomic orbitals used to share or hold lone
    pairs of electrons
    8.10 Lewis Structures
    A. Electrons and Stability
    1. "the most important requirement for the formation of a stable
    compound is that the atoms achieve noble gas configurations
    2.
  141. atomic
    relating to the smallest component of an element
    "A molecule is composed of atoms that are bound together by sharing
    pairs of electrons using the atomic orbitals of the bound atoms
    D. Derivations of the Localized Model
    1.
  142. shorten
    make short or shorter
    As the number of shared electrons increases, the bond length shortens
    (see table 8.5)
    C. Bond Energy and Enthalpy (using bond energy to calculate approximate
    energies for rxns)
    1.
  143. approximate
    not quite exact or correct
    As the number of shared electrons increases, the bond length shortens
    (see table 8.5)
    C. Bond Energy and Enthalpy (using bond energy to calculate approximate
    energies for rxns)
    1.
  144. row
    an arrangement of objects or people side by side in a line
    Arrange the remaining atoms to satisfy the duet rule for
    hydrogen and the octet rule for the second row elements
    8.11 Exceptions to the Octet Rule
    A. Boron Trifluoride
    1.
  145. VII
    the cardinal number that is the sum of six and one
    Group I loses one electron, Group II loses two, Group VI gains
    two, Group VII gains one….
  146. dot
    a very small circular shape
    Lines instead of dots are used to indicate each
    pair of bonding electrons
    c.
  147. periodic
    happening or recurring at regular intervals
    Placement of elements on the periodic table suggests how many
    electrons are lost or gained to achieve a noble-gas configuration
    a.
  148. sharing
    unselfishly willing to partake with others
    "A molecule is composed of atoms that are bound together by sharing
    pairs of electrons using the atomic orbitals of the bound atoms
    D. Derivations of the Localized Model
    1.
  149. react
    show a response to something
    Metals react with nonmetals
    3.
  150. geometry
    the mathematics of points and lines and curves and surfaces
    Prediction of molecular geometry using VSEPR (valence shell electron
    pair repulsion)
    3.
  151. symmetry
    balance among the parts of something
    Linear, radial or tetrahedral symmetry of charge distribution
    a.
  152. ammonia
    a strong-smelling gas compounded of nitrogen and hydrogen
    The ideal tetrahedral angle is 109.5°
    Comparison of Tetrahedral Bond Angles
    Compound Structure Angle between
    Hydrogens
    Methane

    109.5°
    Ammonia 107°
    Water 104.5°
    2.
  153. minus
    on the negative side or lower end of a scale
    Number of valence electrons on the free atom
    minus
    Number of valence electrons assigned to the atom in the molecule
    a.
  154. adequately
    in a sufficient manner
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  155. minimum
    the smallest possible quantity
    Distance at which the system energy is at a minimum
    2.
  156. calculating
    good at tricking people to get something
    Lattice energy increases as the ionic charge increases and the
    distance between anions and cations decreases
    8.6 Partial Ionic Character of Covalent Bonds
    A. Calculating Percent Ionic Character
    x100%
    calculated dipole moment of X Y
    measured dipole moment of X Y
    Percent ionic character
    ø
    ö
    è
    æ -
    =
    + -
    B. Ionic vs.
  157. requirement
    necessary activity
    Description of the type of atomic orbitals used to share or hold lone
    pairs of electrons
    8.10 Lewis Structures
    A. Electrons and Stability
    1. "the most important requirement for the formation of a stable
    compound is that the atoms achieve noble gas configurations
    2.
  158. nucleus
    a part of the cell responsible for growth and reproduction
    Electrons are shared by nuclei
    2.
  159. positive
    characterized by or displaying affirmation or acceptance
    Molecules with a somewhat negative end and a somewhat positive end
    (a dipole moment)
    2.
  160. cubic
    having three dimensions
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  161. formula
    a group of symbols that make a mathematical statement
    Electrons are shared in order to complete the valence
    configurations of both atoms
    B. Predicting Formulas of Ionic Compounds
    1.
  162. evenly
    in a level and regular way
    Electrons are shared evenly
    3.
  163. affinity
    a natural attraction or feeling of kinship
    Energy change is exothermic (negative sign)
    Example: Formation of lithium fluoride
    Process Description Energy Change (kJ)
    Li(s) ‡ Li(g) Sublimation energy 161
    Li(g) ‡ Li
    +
    (g) + e
    -
    Ionization energy 520
    1/2F2 ‡ F(g) Bond energy (1/2 mole) 77
    F(g) + e
    -
    ‡ F
    -
    (g) Electron affinity -328
    Li
    +
    (g) + F
    -
    (g) ‡ LiF(s) Lattice energy -1047
    Li(s) + 1/2F2(g) ‡ LiF(s) DH -617
    3.
  164. assign
    select something or someone for a specific purpose
    Number of valence electrons on the free atom
    minus
    Number of valence electrons assigned to the atom in the molecule
    a.
  165. satisfy
    meet the requirements or expectations of
    Arrange the remaining atoms to satisfy the duet rule for
    hydrogen and the octet rule for the second row elements
    8.11 Exceptions to the Octet Rule
    A. Boron Trifluoride
    1.
  166. using
    an act that exploits or victimizes someone
    As the number of shared electrons increases, the bond length shortens
    (see table 8.5)
    C. Bond Energy and Enthalpy (using bond energy to calculate approximate
    energies for rxns)
    1.
  167. prediction
    a statement made about the future
    Prediction of molecular geometry using VSEPR (valence shell electron
    pair repulsion)
    3.
  168. determine
    find out or learn with certainty, as by making an inquiry
    We will not use the subtraction of electronegativities to determine ionic
    character.
  169. end up
    finally be or do something
    Atoms end up with fractional charges
    (1) d+ or d-
    8.2 Electronegativity
    A. Electronegativity
    1.
  170. depicted
    represented graphically by sketch or design or lines
    The actual structure is an average of the depicted resonance
    structures
    C. Odd Electron Molecules
    1.
  171. transfer
    move from one place to another
    Electrons are transferred
    2.
  172. visual
    relating to or using sight
    Provides a visual tool to understanding chemical structure
    B. Weaknesses of the Bond Model
    1.
  173. gas
    state of matter distinguished from solid and liquid states
    See table 8.2 in your text
    8.4 Ions: Electron Configurations and Sizes
    A. Bonding and Noble Gas Electron Configurations
    1.
  174. valid
    well grounded in logic or truth or having legal force
    When more than one valid Lewis structure can be written for a
    particular molecule
    2.
  175. sum
    a quantity obtained by the addition of a group of numbers
    DH = sum of the energies required to break old bonds(endothermic)
    +
    sum of the energies released in forming new bonds (exothermic)
    2.
  176. arrangement
    an orderly grouping considered as a unit
    Valence electron arrangement using Lewis structures
    2.
  177. greater
    greater in size or importance or degree
    Ions paired have lower energy (greater stability) than separated ions
    B. Coulomb's Law
    1.
    ø
    ö
    è
    æ
    = ×
    -
    r
    Q Q
    E x J nm
    19 1 2
    2.31 10
    a.
  178. total
    the whole amount
    Formulas for compounds are balanced so that the total positive ionic
    charge is equal to the total negative ionic charge
    Al O
    2
    3
    3
    2
    + -
    Total positive = +6
    Total negative = -6
    C. Sizes of Ions
    1.
  179. increase
    a process of becoming larger or longer or more numerous
    Electronegativity generally increases across a period (why?)
  180. surround
    extend on all sides of simultaneously; encircle
    Elements carbon and beyond form stable molecules when they
    are surrounded by eight electrons
    B. Writing Lewis Structures
    1.
  181. compose
    form the substance of
    "A molecule is composed of atoms that are bound together by sharing
    pairs of electrons using the atomic orbitals of the bound atoms
    D. Derivations of the Localized Model
    1.
  182. calculation
    determination by mathematical or logical methods
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  183. indicate
    designate a place, direction, person, or thing
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  184. parent
    a father or mother
    Anions are larger than the parent atom
    2.
  185. closest
    within the shortest distance
    If nonequivalent Lewis structures exist for a species, those with the
    formal charges closest to zero, and with negative formal charges on
    the most electronegative atoms are considered the best candidates
    2.
  186. concept
    an abstract or general idea inferred from specific instances
    AP Chemistry
    A. Allan
    Chapter 8 Notes - Bonding: General Concepts
    8.1 Types of Chemical Bonds
    A. Ionic Bonding
    1.
  187. experimental
    of the nature of or undergoing a trial
    Only experimental evidence can conclusively determine the correct
    bonding situation in a molecule
    8.13 Molecular Structure: The VSEPR Model
    A. Valence Shell Electron Pair Repulsion (VSEPR)
    1.
  188. average
    an intermediate scale value regarded as normal or usual
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  189. dependent on
    determined by conditions or circumstances that follow
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  190. melt
    reduce or cause to be reduced from a solid to a liquid state
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  191. triple
    having three units or components or elements
    Triple bonds - 3 pairs of shared electrons
    Multiple Bonds, Average Energy (kJ/mole)
    C=C 614 N=O 607
    CºC 839 N=N 418
    O=O 495 NºN 941
    C=O 745 CºN 891
    CºO 1072 C=N 615
    4.
  192. attractive
    pleasing to the eye or mind as through beauty or charm
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  193. connect
    fasten or put together two or more pieces
    A resonance structure is drawn by writing the three
    variant structures, connected by a double-headed
    arrow
    B. Resonance
    1.
  194. chemistry
    the science of matter
    AP Chemistry
    A. Allan
    Chapter 8 Notes - Bonding: General Concepts
    8.1 Types of Chemical Bonds
    A. Ionic Bonding
    1.
  195. zero
    the mathematical symbol 0 denoting absence of quantity
    If nonequivalent Lewis structures exist for a species, those with the
    formal charges closest to zero, and with negative formal charges on
    the most electronegative atoms are considered the best candidates
    2.
  196. character
    a property that defines the individual nature of something
    Greater electronegativity difference between two elements means less
    covalent character and greater ionic character
    2.
  197. require
    have need of
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  198. ratio
    relation with respect to comparative quantity or magnitude
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  199. balanced
    being in a state of proper equilibrium
    Formulas for compounds are balanced so that the total positive ionic
    charge is equal to the total negative ionic charge
    Al O
    2
    3
    3
    2
    + -
    Total positive = +6
    Total negative = -6
    C. Sizes of Ions
    1.
  200. use
    put into service
    We will not use the subtraction of electronegativities to determine ionic
    character.
  201. trend
    a general tendency to change, as of opinion
    The ability of an atom in a molecule to attract shared electrons to itself
    B. Electronegativity Trends
    1.
  202. size
    the physical magnitude of something (how big it is)
    See table 8.2 in your text
    8.4 Ions: Electron Configurations and Sizes
    A. Bonding and Noble Gas Electron Configurations
    1.
  203. identify
    recognize as being
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  204. shell
    the outer covering of an animal
    Prediction of molecular geometry using VSEPR (valence shell electron
    pair repulsion)
    3.
  205. form
    a perceptual structure
    The change in energy that takes place when separated gaseous ions
    are packed together to form an ionic solid
    M
    +
    (g) + X
    -
    (g) ‡ MX (s)
    2.
  206. obey
    comply with; do what one is told
    Boron often forms molecules that obey the octet
    rule
    B. Sulfur Hexafluoride
    1.
  207. metal
    a chemical element or alloy that is usually a shiny solid
    Metals react with nonmetals
    3.
  208. gain
    obtain
    Placement of elements on the periodic table suggests how many
    electrons are lost or gained to achieve a noble-gas configuration
    a.
  209. contain
    hold or have within
    Percent ionic character is difficult to calculate for compounds
    containing polyatomic ions8.7 The Covalent Chemical Bond: A Model
    A. Strengths of the Bond Model
    1.
  210. electric
    using or providing the flow of charge through a conductor
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  211. carbon
    an abundant nonmetallic element in all organic compounds
    Elements carbon and beyond form stable molecules when they
    are surrounded by eight electrons
    B. Writing Lewis Structures
    1.
  212. extra
    more than is needed, desired, or required
    If extra electrons remain, place them on
    elements having available d orbitals
    a.
  213. principally
    for the most part
    The structure around a given atom is determined principally by
    minimizing electron-pair repulsions
    2.
  214. yielding
    a verbal act of admitting defeat
    Non-bonding and bonding electron pairs will be as far apart as possible
    Arrangement of Electron Pairs Around an Atom Yielding Minimum
    Repulsion
    # of Electron
    Pairs
    Shape Arrangement of Electron Pairs
    2 Linear

    3 Trigonal Planar
    4 Tetrahedral
    5 Trigonal bipyramidal

    6 Octahedral
    B. Effect of Unshared Electron Pairs
    1.
  215. noble
    of or belonging to hereditary aristocracy
    See table 8.2 in your text
    8.4 Ions: Electron Configurations and Sizes
    A. Bonding and Noble Gas Electron Configurations
    1.
  216. separated
    being or feeling set or kept apart from others
    Ions paired have lower energy (greater stability) than separated ions
    B. Coulomb's Law
    1.
    ø
    ö
    è
    æ
    = ×
    -
    r
    Q Q
    E x J nm
    19 1 2
    2.31 10
    a.
  217. distance
    the property created by the space between two objects
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  218. act as
    function as or act like
    BF3 is electron deficient and acts as a Lewis acid
    (electron pair acceptor)
    3.
  219. phenomenon
    any state or process known through the senses
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  220. partial
    being or affecting only a segment
    Lattice energy increases as the ionic charge increases and the
    distance between anions and cations decreases
    8.6 Partial Ionic Character of Covalent Bonds
    A. Calculating Percent Ionic Character
    x100%
    calculated dipole moment of X Y
    measured dipole moment of X Y
    Percent ionic character
    ø
    ö
    è
    æ -
    =
    + -
    B. Ionic vs.
  221. attain
    gain with effort
    Electrons are transferred until each species attains a noble gas
    electron configuration
    2.
  222. exhibit
    make visible or apparent
    When a molecule exhibits resonance, ANY of the resonance structures
    can be used to predict the molecular structure using the VSEPR model
    D. Molecules Containing No Single Central Atom
    1.
  223. melted
    changed from a solid to a liquid state
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  224. species
    taxonomic group whose members can interbreed
    Electrons are transferred until each species attains a noble gas
    electron configuration
    2.
  225. overall
    involving only main features
    The sum of the formal charges of all atoms in a given molecule or ion
    must equal the overall charge on that species
    a.
  226. generally
    usually; as a rule
    Electronegativity generally increases across a period (why?)
  227. solid
    not soft or yielding to pressure
    The change in energy that takes place when separated gaseous ions
    are packed together to form an ionic solid
    M
    +
    (g) + X
    -
    (g) ‡ MX (s)
    2.
  228. associate
    bring or come into action
    Associates quantities of energy with the formation of bonds between
    elements
    2.
  229. arrow
    projectile with a thin shaft intended to be shot from a bow
    A resonance structure is drawn by writing the three
    variant structures, connected by a double-headed
    arrow
    B. Resonance
    1.
  230. lose
    fail to keep or to maintain
    Placement of elements on the periodic table suggests how many
    electrons are lost or gained to achieve a noble-gas configuration
    a.
  231. definition
    a brief explanation of the meaning of a word or phrase
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  232. attract
    exert a force on
    The ability of an atom in a molecule to attract shared electrons to itself
    B. Electronegativity Trends
    1.
  233. between
    in the interval
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  234. divide
    a serious disagreement between two groups of people
    Shared electrons are divided equally between the sharing atoms2.
  235. arrange
    put into a proper or systematic order
    Arrange the remaining atoms to satisfy the duet rule for
    hydrogen and the octet rule for the second row elements
    8.11 Exceptions to the Octet Rule
    A. Boron Trifluoride
    1.
  236. text
    the words of something written
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  237. equal
    having the same quantity, value, or measure as another
    Formulas for compounds are balanced so that the total positive ionic
    charge is equal to the total negative ionic charge
    Al O
    2
    3
    3
    2
    + -
    Total positive = +6
    Total negative = -6
    C. Sizes of Ions
    1.
  238. tool
    an implement used to perform a task or job
    Provides a visual tool to understanding chemical structure
    B. Weaknesses of the Bond Model
    1.
  239. 120
    the cardinal number that is the product of ten and twelve
    Lone pairs do not cause distortion when bond angles are 120° or
    greater
    C. VSEPR and Multiple Bonds
    1.
  240. bound
    confined by bonds
    "A molecule is composed of atoms that are bound together by sharing
    pairs of electrons using the atomic orbitals of the bound atoms
    D. Derivations of the Localized Model
    1.
  241. actual
    existing in fact
    Bonds are not actual physical structures
    2.
  242. take place
    come to pass
    The change in energy that takes place when separated gaseous ions
    are packed together to form an ionic solid
    M
    +
    (g) + X
    -
    (g) ‡ MX (s)
    2.
  243. fewer
    quantifier meaning a smaller number of
    B and Be (second row) often have fewer then eight electrons around
    them, and form electron deficient, highly reactive molecules
    3.
  244. number
    a concept of quantity involving zero and units
    Ions with the same number of electrons
    b.
  245. dependent
    a person who relies on another person for support
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  246. separate
    standing apart; not attached to or supported by anything
    Ions paired have lower energy (greater stability) than separated ions
    B. Coulomb's Law
    1.
    ø
    ö
    è
    æ
    = ×
    -
    r
    Q Q
    E x J nm
    19 1 2
    2.31 10
    a.
  247. group
    any number of entities (members) considered as a unit
    Group I loses one electron, Group II loses two, Group VI gains
    two, Group VII gains one….
  248. description
    the act of depicting something
    Energy change is exothermic (negative sign)
    Example: Formation of lithium fluoride
    Process Description Energy Change (kJ)
    Li(s) ‡ Li(g) Sublimation energy 161
    Li(g) ‡ Li
    +
    (g) + e
    -
    Ionization energy 520
    1/2F2 ‡ F(g) Bond energy (1/2 mole) 77
    F(g) + e
    -
    ‡ F
    -
    (g) Electron affinity -328
    Li
    +
    (g) + F
    -
    (g) ‡ LiF(s) Lattice energy -1047
    Li(s) + 1/2F2(g) ‡ LiF(s) DH -617
    3.
  249. force
    influence that results in motion, stress, etc. when applied
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  250. apart
    separated or at a distance in place or position or time
    Energy is given off (bond energy) when two atoms achieve greater
    stability together than apart
    D. Covalent Bonds
    1.
  251. measured
    having notes of fixed rhythmic value
    Lattice energy increases as the ionic charge increases and the
    distance between anions and cations decreases
    8.6 Partial Ionic Character of Covalent Bonds
    A. Calculating Percent Ionic Character
    x100%
    calculated dipole moment of X Y
    measured dipole moment of X Y
    Percent ionic character
    ø
    ö
    è
    æ -
    =
    + -
    B. Ionic vs.
  252. packed
    filled to capacity
    The change in energy that takes place when separated gaseous ions
    are packed together to form an ionic solid
    M
    +
    (g) + X
    -
    (g) ‡ MX (s)
    2.
  253. reaction
    an idea evoked by some experience
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  254. calculated
    carefully thought out in advance
    Lattice energy increases as the ionic charge increases and the
    distance between anions and cations decreases
    8.6 Partial Ionic Character of Covalent Bonds
    A. Calculating Percent Ionic Character
    x100%
    calculated dipole moment of X Y
    measured dipole moment of X Y
    Percent ionic character
    ø
    ö
    è
    æ -
    =
    + -
    B. Ionic vs.
  255. equal to
    having the requisite qualities for
    Formulas for compounds are balanced so that the total positive ionic
    charge is equal to the total negative ionic charge
    Al O
    2
    3
    3
    2
    + -
    Total positive = +6
    Total negative = -6
    C. Sizes of Ions
    1.
  256. percent
    a proportion in relation to a whole
    Lattice energy increases as the ionic charge increases and the
    distance between anions and cations decreases
    8.6 Partial Ionic Character of Covalent Bonds
    A. Calculating Percent Ionic Character
    x100%
    calculated dipole moment of X Y
    measured dipole moment of X Y
    Percent ionic character
    ø
    ö
    è
    æ -
    =
    + -
    B. Ionic vs.
  257. tend
    have a disposition to do or be something; be inclined
    Lone (unshared) electron pairs require more room than bonding pairs
    (they have greater repulsive forces) and tend to compress the angles
    between bonding pairs
    3.
  258. assigned
    appointed to a post or duty
    Number of valence electrons on the free atom
    minus
    Number of valence electrons assigned to the atom in the molecule
    a.
  259. type
    a subdivision of a particular kind of thing
    AP Chemistry
    A. Allan
    Chapter 8 Notes - Bonding: General Concepts
    8.1 Types of Chemical Bonds
    A. Ionic Bonding
    1.
  260. write
    name the letters that comprise the accepted form of
    Elements carbon and beyond form stable molecules when they
    are surrounded by eight electrons
    B. Writing Lewis Structures
    1.
  261. double
    consisting of or involving two parts or components usually in pairs
    Double bonds - 2 pairs of shared electrons
    3.
  262. relationship
    a mutual connection between people
    Allows the drawing of structures showing the spatial relationship
    between atoms in a molecule
    3.
  263. headed
    having a head of a specified kind or anything that serves as a head; often used in combination
    A resonance structure is drawn by writing the three
    variant structures, connected by a double-headed
    arrow
    B. Resonance
    1.
  264. at work
    on the job
    Forces at work
    a.
  265. develop
    progress or evolve through a process of natural growth
    Look at real 3-dimensional, rotatable models to develop predictive
    skills
    E. How Well Does VSEPR Work?
  266. acid
    a sour water-soluble compound with a pH of less than 7
    BF3 is electron deficient and acts as a Lewis acid
    (electron pair acceptor)
    3.
  267. center
    an area that is in the middle of some larger region
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  268. pack
    a convenient package or parcel (as of cigarettes or film)
    The change in energy that takes place when separated gaseous ions
    are packed together to form an ionic solid
    M
    +
    (g) + X
    -
    (g) ‡ MX (s)
    2.
  269. used to
    in the habit
    Description of the type of atomic orbitals used to share or hold lone
    pairs of electrons
    8.10 Lewis Structures
    A. Electrons and Stability
    1. "the most important requirement for the formation of a stable
    compound is that the atoms achieve noble gas configurations
    2.
  270. balance
    harmonious arrangement or relation of parts within a whole
    Formulas for compounds are balanced so that the total positive ionic
    charge is equal to the total negative ionic charge
    Al O
    2
    3
    3
    2
    + -
    Total positive = +6
    Total negative = -6
    C. Sizes of Ions
    1.
  271. assume
    take to be the case or to be true
    When necessary to exceed the octet rule for one of several third
    row elements, assume that the extra electrons be placed on the
    central atom
    8.12 Resonance
    A. Nitrate ion
    1.
  272. single
    existing alone or consisting of one entity or part or aspect or individual
    Single bonds - 1 pair of shared electrons
    2.
  273. nuclear
    constituting the core or central part
    Size decreases as the nuclear charge Z increases8.5 Formation of Binary Ionic Compounds
    A. Lattice Energy
    1.
  274. experiment
    the act of conducting a controlled test or investigation
    Experiments show that all N-O bonds are equal
    2.
  275. central
    in or near an inner area
    When necessary to exceed the octet rule for one of several third
    row elements, assume that the extra electrons be placed on the
    central atom
    8.12 Resonance
    A. Nitrate ion
    1.
  276. comparison
    the act of examining resemblances
    The ideal tetrahedral angle is 109.5°
    Comparison of Tetrahedral Bond Angles
    Compound Structure Angle between
    Hydrogens
    Methane

    109.5°
    Ammonia 107°
    Water 104.5°
    2.
  277. distribution
    the act of spreading or apportioning
    Linear, radial or tetrahedral symmetry of charge distribution
    a.
  278. candidate
    someone who is considered for something
    If nonequivalent Lewis structures exist for a species, those with the
    formal charges closest to zero, and with negative formal charges on
    the most electronegative atoms are considered the best candidates
    2.
  279. process
    a particular course of action intended to achieve a result
    Energy change is exothermic (negative sign)
    Example: Formation of lithium fluoride
    Process Description Energy Change (kJ)
    Li(s) ‡ Li(g) Sublimation energy 161
    Li(g) ‡ Li
    +
    (g) + e
    -
    Ionization energy 520
    1/2F2 ‡ F(g) Bond energy (1/2 mole) 77
    F(g) + e
    -
    ‡ F
    -
    (g) Electron affinity -328
    Li
    +
    (g) + F
    -
    (g) ‡ LiF(s) Lattice energy -1047
    Li(s) + 1/2F2(g) ‡ LiF(s) DH -617
    3.
  280. around
    in the area or vicinity
    Note that boron only has six electrons around it
    2.
  281. salt
    white crystalline form of especially sodium chloride used to season and preserve food
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  282. be given
    have a tendency or disposition to do or be something
    Energy is given off (bond energy) when two atoms achieve greater
    stability together than apart
    D. Covalent Bonds
    1.
  283. note
    a brief written record
    AP Chemistry
    A. Allan
    Chapter 8 Notes - Bonding: General Concepts
    8.1 Types of Chemical Bonds
    A. Ionic Bonding
    1.
  284. difference
    the quality of being unlike or dissimilar
    Greater electronegativity difference between two elements means less
    covalent character and greater ionic character
    2.
  285. represent
    be a delegate or spokesperson for
    A single Lewis structure cannot represent the
    nitrate ion
    3.
  286. required
    necessary by rule
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  287. apply
    employ for a particular purpose
    Apply the principal of distancing shared and unshared electron pairs
    2.
  288. suggest
    make a proposal; declare a plan for something
    Placement of elements on the periodic table suggests how many
    electrons are lost or gained to achieve a noble-gas configuration
    a.
  289. work in
    add by mixing or blending on or attaching
    For non-ionic compounds, VSEPR works in most cases
  290. exception
    an instance that does not conform to a rule
    Arrange the remaining atoms to satisfy the duet rule for
    hydrogen and the octet rule for the second row elements
    8.11 Exceptions to the Octet Rule
    A. Boron Trifluoride
    1.
  291. effective
    producing or capable of producing an intended result
    For the VSEPR model, multiple bonds count as one effective electron
    pair
    2.
  292. writing
    symbols imprinted on a surface to represent sounds or words
    Elements carbon and beyond form stable molecules when they
    are surrounded by eight electrons
    B. Writing Lewis Structures
    1.
  293. sign
    a visible clue that something has happened or is present
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  294. yield
    give or supply
    Non-bonding and bonding electron pairs will be as far apart as possible
    Arrangement of Electron Pairs Around an Atom Yielding Minimum
    Repulsion
    # of Electron
    Pairs
    Shape Arrangement of Electron Pairs
    2 Linear

    3 Trigonal Planar
    4 Tetrahedral
    5 Trigonal bipyramidal

    6 Octahedral
    B. Effect of Unshared Electron Pairs
    1.
  295. odd
    not divisible by two
    The actual structure is an average of the depicted resonance
    structures
    C. Odd Electron Molecules
    1.
  296. release
    grant freedom to; free from confinement
    DH = sum of the energies required to break old bonds(endothermic)
    +
    sum of the energies released in forming new bonds (exothermic)
    2.
  297. weakness
    a flaw
    Provides a visual tool to understanding chemical structure
    B. Weaknesses of the Bond Model
    1.
  298. break
    destroy the integrity of
    DH = sum of the energies required to break old bonds(endothermic)
    +
    sum of the energies released in forming new bonds (exothermic)
    2.
  299. table
    furniture having a smooth flat top supported by legs
    See table 8.2 in your text
    8.4 Ions: Electron Configurations and Sizes
    A. Bonding and Noble Gas Electron Configurations
    1.
  300. formed
    having or given a form or shape
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  301. are
    a unit of surface area equal to 100 square meters
    Electrons are transferred
    2.
  302. ideal
    a principle or value that one hopes to attain or conform to
    The ideal tetrahedral angle is 109.5°
    Comparison of Tetrahedral Bond Angles
    Compound Structure Angle between
    Hydrogens
    Methane

    109.5°
    Ammonia 107°
    Water 104.5°
    2.
  303. eight
    the cardinal number that is the sum of seven and one
    Elements carbon and beyond form stable molecules when they
    are surrounded by eight electrons
    B. Writing Lewis Structures
    1.
  304. moment
    an indefinitely short time
    Bond Polarity and Dipole Moments
    A. Dipolar Molecules
    1.
  305. change
    become different in some particular way
    The change in energy that takes place when separated gaseous ions
    are packed together to form an ionic solid
    M
    +
    (g) + X
    -
    (g) ‡ MX (s)
    2.
  306. correct
    free from error; especially conforming to fact or truth
    Only experimental evidence can conclusively determine the correct
    bonding situation in a molecule
    8.13 Molecular Structure: The VSEPR Model
    A. Valence Shell Electron Pair Repulsion (VSEPR)
    1.
  307. somewhat
    to a small degree or extent
    Molecules with a somewhat negative end and a somewhat positive end
    (a dipole moment)
    2.
  308. belong
    be owned by; be in the possession of
    Lone pair (unshared) electrons belong completely to the atom in
    question
    b.
  309. exist
    have a presence
    If nonequivalent Lewis structures exist for a species, those with the
    formal charges closest to zero, and with negative formal charges on
    the most electronegative atoms are considered the best candidates
    2.
  310. second
    coming next after the first in position in space or time
    Arrange the remaining atoms to satisfy the duet rule for
    hydrogen and the octet rule for the second row elements
    8.11 Exceptions to the Octet Rule
    A. Boron Trifluoride
    1.
  311. remain
    continue in a place, position, or situation
    Arrange the remaining atoms to satisfy the duet rule for
    hydrogen and the octet rule for the second row elements
    8.11 Exceptions to the Octet Rule
    A. Boron Trifluoride
    1.
  312. shape
    a perceptual structure
    Non-bonding and bonding electron pairs will be as far apart as possible
    Arrangement of Electron Pairs Around an Atom Yielding Minimum
    Repulsion
    # of Electron
    Pairs
    Shape Arrangement of Electron Pairs
    2 Linear

    3 Trigonal Planar
    4 Tetrahedral
    5 Trigonal bipyramidal

    6 Octahedral
    B. Effect of Unshared Electron Pairs
    1.
  313. available
    obtainable or accessible and ready for use or service
    If extra electrons remain, place them on
    elements having available d orbitals
    a.
  314. quantity
    how much there is or how many there are of something
    Associates quantities of energy with the formation of bonds between
    elements
    2.
  315. skill
    an ability that has been acquired by training
    Look at real 3-dimensional, rotatable models to develop predictive
    skills
    E. How Well Does VSEPR Work?
  316. remaining
    not used up
    Arrange the remaining atoms to satisfy the duet rule for
    hydrogen and the octet rule for the second row elements
    8.11 Exceptions to the Octet Rule
    A. Boron Trifluoride
    1.
  317. composed
    serenely self-possessed and free from agitation
    "A molecule is composed of atoms that are bound together by sharing
    pairs of electrons using the atomic orbitals of the bound atoms
    D. Derivations of the Localized Model
    1.
  318. ability
    the quality of having the means or skills to do something
    The ability of an atom in a molecule to attract shared electrons to itself
    B. Electronegativity Trends
    1.
  319. More
    English statesman who opposed Henry VIII's divorce from Catherine of Aragon and was imprisoned and beheaded; recalled for his concept of Utopia, the ideal state
    SF6 fills the 3s and 3p orbitals with 8 of the
    valence electrons, and places the other 4 in the
    higher energy 3d orbital
    C. More About the Octet Rule
    1.
  320. surrounded
    confined on all sides
    Elements carbon and beyond form stable molecules when they
    are surrounded by eight electrons
    B. Writing Lewis Structures
    1.
  321. divided
    separated into parts or pieces
    Shared electrons are divided equally between the sharing atoms2.
  322. length
    the linear extent in space from one end to the other
    Q1 and Q2 are numerical ion charges
    c. r = distance between ion center in nanometers
    d. negative sign indicates an attractive force
    C. Bond Length (covalent)
    1.
  323. provide
    give something useful or necessary to
    Provides a visual tool to understanding chemical structure
    B. Weaknesses of the Bond Model
    1.
  324. constant
    uninterrupted in time and indefinitely long continuing
    The lattice formed by alkali metals and halogens (1:1 ratio) is cubic
    except for cesium salts
    B. Lattice Energy Calculations
    1.
    ø
    ö
    è
    æ
    =
    r
    Q Q
    Lattice Energy k
    1 2
    a. k = a proportionality constant dependent on the solid structure
    and the electron configuration
    b.
  325. fill
    make full, also in a metaphorical sense
    SF6 fills the 3s and 3p orbitals with 8 of the
    valence electrons, and places the other 4 in the
    higher energy 3d orbital
    C. More About the Octet Rule
    1.
  326. connected
    joined or linked together
    A resonance structure is drawn by writing the three
    variant structures, connected by a double-headed
    arrow
    B. Resonance
    1.
  327. smaller
    small or little relative to something else
    Cations are smaller than the parent atom
    3.
  328. understanding
    the condition of someone who knows and comprehends
    Provides a visual tool to understanding chemical structure
    B. Weaknesses of the Bond Model
    1.
  329. great
    a person who has achieved distinction in some field
    Ions paired have lower energy (greater stability) than separated ions
    B. Coulomb's Law
    1.
    ø
    ö
    è
    æ
    = ×
    -
    r
    Q Q
    E x J nm
    19 1 2
    2.31 10
    a.
  330. practical
    guided by experience and observation rather than theory
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  331. for one
    as a particular one of several possibilities
    When necessary to exceed the octet rule for one of several third
    row elements, assume that the extra electrons be placed on the
    central atom
    8.12 Resonance
    A. Nitrate ion
    1.
  332. drawing
    a representation of forms or objects on a surface by means of lines
    Allows the drawing of structures showing the spatial relationship
    between atoms in a molecule
    3.
  333. third
    one of three equal parts of a divisible whole
    Third row and heavier elements often satisfy (or exceed) the octet rule
    5.
  334. highly
    to a great degree or extent; favorably or with much respect
    B and Be (second row) often have fewer then eight electrons around
    them, and form electron deficient, highly reactive molecules
    3.
  335. showing
    the display of a motion picture
    Allows the drawing of structures showing the spatial relationship
    between atoms in a molecule
    3.
  336. principal
    main or most important
    Apply the principal of distancing shared and unshared electron pairs
    2.
  337. explain
    make plain and comprehensible
    Bonds can not adequately explain some phenomena
    a. resonance
    8.8 Covalent Bond Energies and Chemical Reactions
    A. Average Bond Energies
    Process Energy Required (kJ/mol)
    CH4(g) ‡ CH3(g) + H(g) 435
    CH3(g) ‡ CH2(g) + H(g) 453
    CH2(g) ‡ CH(g) + H(g) 425
    CH(g) ‡ C(g) + H(g) 339
    Total 1652
    Average 413
    B. Multiple Bonds
    1.
  338. often
    many times at short intervals
    Boron often forms molecules that obey the octet
    rule
    B. Sulfur Hexafluoride
    1.
  339. together
    in contact with each other or in proximity
    Energy is given off (bond energy) when two atoms achieve greater
    stability together than apart
    D. Covalent Bonds
    1.
  340. add
    join or combine or unite with others
    Add up the TOTAL number of valence electrons from all atoms
    b.
  341. completely
    with everything necessary
    Lone pair (unshared) electrons belong completely to the atom in
    question
    b.
  342. physical
    involving the body as distinguished from the mind or spirit
    Bonds are not actual physical structures
    2.
  343. equally
    in a balanced or impartial way
    Shared electrons are divided equally between the sharing atoms2.
  344. used
    previously owned by another
    Description of the type of atomic orbitals used to share or hold lone
    pairs of electrons
    8.10 Lewis Structures
    A. Electrons and Stability
    1. "the most important requirement for the formation of a stable
    compound is that the atoms achieve noble gas configurations
    2.
  345. on that
    on that
    The sum of the formal charges of all atoms in a given molecule or ion
    must equal the overall charge on that species
    a.
  346. given
    acknowledged as a supposition
    Energy is given off (bond energy) when two atoms achieve greater
    stability together than apart
    D. Covalent Bonds
    1.
  347. draw
    cause to move by pulling
    Allows the drawing of structures showing the spatial relationship
    between atoms in a molecule
    3.
  348. pure
    free of extraneous elements of any kind
    Pure covalent (non-polar covalent)
    a.
  349. larger
    large or big relative to something else
    Anions are larger than the parent atom
    2.
  350. current
    occurring in or belonging to the present time
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  351. measure
    determine the dimensions of something or somebody
    Lattice energy increases as the ionic charge increases and the
    distance between anions and cations decreases
    8.6 Partial Ionic Character of Covalent Bonds
    A. Calculating Percent Ionic Character
    x100%
    calculated dipole moment of X Y
    measured dipole moment of X Y
    Percent ionic character
    ø
    ö
    è
    æ -
    =
    + -
    B. Ionic vs.
  352. conduct
    the way a person behaves toward other people
    This text uses a practical definition to identify ionic
    compounds:
    Any compound that conducts an electric current when melted is an
    ionic compound.8.3
  353. fit
    meeting adequate standards for a purpose
    Does not fit localized electron model
    D. Formal Charge
    1.
  354. allow
    make it possible for something to happen
    Allows the drawing of structures showing the spatial relationship
    between atoms in a molecule
    3.
  355. place
    a point located with respect to surface features of a region
    The change in energy that takes place when separated gaseous ions
    are packed together to form an ionic solid
    M
    +
    (g) + X
    -
    (g) ‡ MX (s)
    2.
  356. end
    either extremity of something that has length
    Atoms end up with fractional charges
    (1) d+ or d-
    8.2 Electronegativity
    A. Electronegativity
    1.
  357. consider
    think about carefully; weigh
    If nonequivalent Lewis structures exist for a species, those with the
    formal charges closest to zero, and with negative formal charges on
    the most electronegative atoms are considered the best candidates
    2.
  358. count
    determine the number or amount of
    For the VSEPR model, multiple bonds count as one effective electron
    pair
    2.
  359. drawn
    showing the wearing effects of overwork or care or suffering
    A resonance structure is drawn by writing the three
    variant structures, connected by a double-headed
    arrow
    B. Resonance
    1.
  360. show
    make visible or noticeable
    Allows the drawing of structures showing the spatial relationship
    between atoms in a molecule
    3.
  361. determined
    having been learned or found especially by investigation
    The structure around a given atom is determined principally by
    minimizing electron-pair repulsions
    2.
  362. evidence
    knowledge on which to base belief
    Only experimental evidence can conclusively determine the correct
    bonding situation in a molecule
    8.13 Molecular Structure: The VSEPR Model
    A. Valence Shell Electron Pair Repulsion (VSEPR)
    1.
Created on Tue Jan 10 23:32:49 EST 2012

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