Chapter 8

Question 1

Angular

Answer 1

A term used to describe the molecular geometry of a molecule that has two atoms bonded to a central atom and one or more unshared pairs on the central atom (AB₂U or AB₂U₂). Also called V-shaped or bent.

Question 2

Central atom

Answer 2

An atom in a molecuel or polyatomic ion that is bonded to more than one other atom

Question 3

Electronic geometry

Answer 3

The geometric arragnement of orbitals containing the shared and unshared electron pairs surroundingt eh central atom of a molecule or polyatomic ion

Question 4

Hybridization

Answer 4

The mixing of a set of atomic orbitals on an atom to form a new set of hybrid orbitals with the same total electron capacity and with properties and energies intermediate between those of the original unhybridized orbitals

Question 5

Hybrid orbitals

Answer 5

Orbitals formed on an atom by the process of hybridization

Question 6

Lewis formula

Answer 6

A method of representing a molecule or formula unit by showing atoms and only outer-shell electrons; does not show shape

Question 7

Linear

Answer 7

A term used to describe the electronic geometry around a central atom that has two regions of high electron density. Also used to describe the molecular geometry of a moelcule or polyatomic ion that has one atom in the center bonded to two atoms on opposite sides (180º) of the central atom (AB₂ or AB₂U₂)

Question 8

Molecular geometry

Answer 8

The arrangement of atoms (not unshared pairs of electrons) around a central atom of a molecule or polyatomic ion

Question 9

Octahedral

Answer 9

A term used to describe the electronic geometry around a central atom that has six regions of high electron density. Also used to describe the molecular geometry of a moelcule or polyatomic ion that has one atom in the center bonded to six atoms at the corners of an octahedrom (AB₆)

Question 10

Overlap of obritals

Answer 10

The interaction of orbitals on different atoms in the same region of space

Question 11

Pi (π) bond

Answer 11

A bond resulting from the side-on overlap of atomic orbitals, in which the regions of electron sharing are on opposite sides of and parallel to an imaginary line connecting the bonded atoms

Question 12

Seesaw

Answer 12

A term used to describe the molecular geometry of a molecule or polyatomic ion that has four atoms bonded to a central atom and one unshared pair on the central atom (AB₄U)

Question 13

Sigma (σ) bond

Answer 13

A bond resulting from the head-on overlap of atomic orbitals, in which the region of electron sharing is along and (cylindrically) symmetrical to an imaginary line connecting the bonded atoms

Question 14

Square planar

Answer 14

A term used to describe molecules and polyatomic ions that have one atom in the center and four atoms at the corners of a square

Question 15

Square pyramidal

Answer 15

A term used to describe the molecular geometry of a molecule or polyatomic ion that has five atoms bonded to a central atom and one unshared pair on the central atom (AB₅U)

Question 16

Tetrahedral

Answer 16

A term used to describe the electronic geometry around a central atom that has four regions of high electron density. Also used to describe the molecular geometry of a molecule or polyatomic ion that has one atom in the center bonded to four atoms at the corners of a tetrahedrom (AB₄)

Question 17

Tetrahedron

Answer 17

A polyhedron with four equal-sized, equilateral triangular faces and four apices (corners)

Question 18

Trigonal bipyramid

Answer 18

A six-sided polyhedron with five apices (corners), consisting of two pyramids sharing a common triangular base

Question 19

Trigonal bipyramidal

Answer 19

A term used to describe the electronic geometry around a central atom that has five regions of high electron density. Also used to describe the molecular geometry of a molecule or polyatomic ion that has one atom in the center bonded to five atoms at the corners of a trigonal bipyramid (AB₅)

Question 20

Trigonal planar

Answer 20

A term used to describe the electronic geometry around a central atom that has three regions of high electron density. Also used to describe the molecular geometry of a molecule or polyatomic ion that has one atom in the center bonded to three atoms at the corners of an equilateral triangle.

Question 21

Trigonal pyramidal

Answer 21

A term used to describe the molecular geometry of a molecule or polyatomic ion that has three atoms bonded to a central atom and one unshared pair on the central atom (AB₃U)

Question 22

T-shaped

Answer 22

A term used to describe the molecular geometry of a molecule or polyatomic ion that has three atoms bonded to a central atom and two unshared pairs on the central atom (AB₃U₂)

Question 23

Valence bond (VB) theory

Answer 23

Assumes that covalent bonds are formed when atomic orbitals on different atoms overlap and electrons are shared

Question 24

Valence shell

Answer 24

The outermost occupied electron shell of an atom

Question 25

Valence shell electron pair repulsion (VSEPR) theory

Answer 25

Assumes that valence electron pairs are arranged around the central element of a molecule or polyatomic ion so that there is maximum separation (and minimum repulsion) among regions of high electron density