[VOCAB] Chapter 9: Models and Chemical Bonding

Question 1

Alloy

Answer 1

A mixture with metallic properties that consists of solid phases of two or more pure elements, a solid-solid solution, or distinct intermediate phases

Question 2

Bond Energy (BE)

Answer 2

(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

Question 3

Bond Length

Answer 3

The distance between the nuclei of two bonded atoms

Question 4

Bond Order

Answer 4

The number of electron pairs shared by two bonded atoms

Question 5

Born-Haber Cycle

Answer 5

A series of hypothetical steps and their enthalpy changes that converts elements to an ionic compound; it is used to calculate the lattice energy

Question 6

Coulomb’s Law

Answer 6

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)

Question 7

Covalent Bond

Answer 7

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

Question 8

Covalent Bonding

Answer 8

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)

Question 9

Double Bond

Answer 9

A covalent bond that consists of two bonding pairs; two atoms sharing four electrons in the form of one σ and one π bond

Question 10

Electronegativity (EN)

Answer 10

The relative ability of a bonded atom to attract shared electrons

Question 11

Electronegativity Difference (ΔEN)

Answer 11

The difference in electronegativities between two bonded atoms

Question 12

Electron-Sea Model

Answer 12

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

Question 13

Infrared (IR) Spectroscopy

Answer 13

An instrumental technique for determining the types of bonds in a covalent molecule by measuring the absorption of IR radiation

Question 14

Ion Pair

Answer 14

A gaseous ionic molecule, formed when an ionic compound vaporizes

Question 15

Ionic Bonding

Answer 15

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)

Question 16

Lattice Energy ΔH°Lattice

Answer 16

The enthalpy change (always positive) that accompanies the separation of 1 mol of a solid ionic compound into gaseous ions

Question 17

Lewis Electron-Dot Symbol

Answer 17

A notation in which the element symbol represents the nucleus and inner electrons and surrounding dots represent the valence electrons

Question 18

Lone Pair

Answer 18

(also unshared pair) An electron pair that is part of an atom’s valence level but not involved in covalent bonding

Question 19

Metallic Bonding

Answer 19

An idealized type of bonding based on the attraction between metal ions and their delocalized valence electrons. (See also electron-sea model)

Question 20

Nonpolar Covalent Bond

Answer 20

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

Question 21

Octet Rule

Answer 21

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)

Question 22

Partial Ionic Character

Answer 22

An estimate of the actual charge separation in a bond (caused by the electronegativity difference of the bonded atoms) relative to complete separation

Question 23

Polar covalent Bond

Answer 23

A covalent bond in which the electron pair is shared unequally, so the bond has partially negative and partially positive poles

Question 24

Shared Pair

Answer 24

Two electrons that are involved in forming a bond. An unshared pair is two electrons that are not involved in forming a bond

Question 25

Single Bond

Answer 25

A bond that consists of one electron pair

Question 26

Triple Bond

Answer 26

A covalent bond that consists of three bonding pairs, two atoms sharing six electrons; one σ and two π bonds