[VOCAB] Chapter 9: Models and Chemical Bonding Flashcards
Alloy
A mixture with metallic properties that consists of solid phases of two or more pure elements, a solid-solid solution, or distinct intermediate phases
Bond Energy (BE)
(also bond enthalpy or bond strength) The standard enthalpy change (always > 0) accompanying the breakage of a given bond in 1 mol of gaseous molecules
Bond Length
The distance between the nuclei of two bonded atoms
Bond Order
The number of electron pairs shared by two bonded atoms
Born-Haber Cycle
A series of hypothetical steps and their enthalpy changes that converts elements to an ionic compound; it is used to calculate the lattice energy
Coulomb’s Law
A law stating that the electrostatic energy between particles A and B is directly proportional to the product of their charges and inversely proportional to the distance between them:
electrostatic energy alpha (charge A x Charge B)/(Distance)
Covalent Bond
A type of bond in which atoms are bonded through the sharing of electrons; the mutual attraction of the nuclei and an electron pair that holds atoms together in a molecule
Covalent Bonding
The idealized bonding type that is based on localized electron-pair sharing between two atoms with little difference in their tendencies to lose or gain electrons (most commonly nonmetals)
Double Bond
A covalent bond that consists of two bonding pairs; two atoms sharing four electrons in the form of one σ and one π bond
Electronegativity (EN)
The relative ability of a bonded atom to attract shared electrons
Electronegativity Difference (ΔEN)
The difference in electronegativities between two bonded atoms
Electron-Sea Model
A qualitative description of metallic bonding proposing that metal atoms pool their valence electrons in a delocalized “sea” of electrons in which the metal ions (nuclei and core electrons) are submerged in an orderly array
Infrared (IR) Spectroscopy
An instrumental technique for determining the types of bonds in a covalent molecule by measuring the absorption of IR radiation
Ion Pair
A gaseous ionic molecule, formed when an ionic compound vaporizes
Ionic Bonding
The idealized type of bonding based on the attraction of oppositely charged ions that arise through electron transfer between atoms with large differences in their tendencies to lose or gain electrons (typically metals and nonmetals)
Lattice Energy ΔH°Lattice
The enthalpy change (always positive) that accompanies the separation of 1 mol of a solid ionic compound into gaseous ions
Lewis Electron-Dot Symbol
A notation in which the element symbol represents the nucleus and inner electrons and surrounding dots represent the valence electrons
Lone Pair
(also unshared pair) An electron pair that is part of an atom’s valence level but not involved in covalent bonding
Metallic Bonding
An idealized type of bonding based on the attraction between metal ions and their delocalized valence electrons. (See also electron-sea model)
Nonpolar Covalent Bond
Type of chemical bond that is formed when electrons are shared equally between two atoms. Thus, in an atom, the number of electrons shared by the adjacent atoms will be the same
Octet Rule
The observation that, when atoms bond, they often lose, gain, or share electrons to attain a filled outer level of eight electrons (or two for H and Li)
Partial Ionic Character
An estimate of the actual charge separation in a bond (caused by the electronegativity difference of the bonded atoms) relative to complete separation
Polar covalent Bond
A covalent bond in which the electron pair is shared unequally, so the bond has partially negative and partially positive poles
Shared Pair
Two electrons that are involved in forming a bond. An unshared pair is two electrons that are not involved in forming a bond
Single Bond
A bond that consists of one electron pair
Triple Bond
A covalent bond that consists of three bonding pairs, two atoms sharing six electrons; one σ and two π bonds
