Chapter 9 Vocab

Question 1

Ionic bonding

Answer 1

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 2

Covalent bonding

Answer 2

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 3

Metallic bonding

Answer 3

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

Question 4

Lewis electron-dot symbol

Answer 4

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

Question 5

Octet rule

Answer 5

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 6

Lattice energy (ΔH°lattice)

Answer 6

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

Question 7

Born-Hager cycle

Answer 7

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 8

Coulomb’s law

Answer 8

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 ∝ (charge A x charge B)/distance

Question 9

Ion pair

Answer 9

A gaseous ionic molecule, formed when an ionic compound vaporizes.

Question 10

Covalent bond

Answer 10

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 11

Bonding pair

Answer 11

(Also shared pair) An electron pair shared by two nuclei; the mutual attraction between the nuclei and the electron pair forms a covalent bond.

Question 12

Lone pair

Answer 12

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

Question 13

Bond order

Answer 13

The number of electron pairs shared by two bonded atoms.

Question 14

Single bond

Answer 14

A bond that consists of one electron pair.

Question 15

Double bond

Answer 15

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 16

Triple bond

Answer 16

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

Question 17

Bond energy (BE)

Answer 17

(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 18

Bond length

Answer 18

The distance between the nuclei of two bonded atoms.

Question 19

Infrared (IR) spectroscopy

Answer 19

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

Question 20

Electronegativity (EN)

Answer 20

The relative ability of a bonded atom to attract shared electrons.

Question 21

Polar covalent bond

Answer 21

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

Question 22

Nonpolar covalent

Answer 22

A covalent bond between identical atoms in which the bonding pair is shared equally.

Question 23

Electronegativity difference (ΔEN)

Answer 23

The difference in electronegativities between two bonded atoms.

Question 24

Partial ionic character

Answer 24

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

Question 25

Electron-sea model

Answer 25

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 26

Alloy

Answer 26

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