Chapter 10

Question 1

Lewis Structure

Answer 1

A structural formula consisting of electron-dot symbols, with lines as bonding pairs and dots as lone pairs

Question 2

resonance structure

Answer 2

One of two or more Lewis structures for a molecule that cannot be adequately depicted by a single structure.

Question 3

resonance hybrid

Answer 3

The weighted average of the resonance structures of a molecule

Question 4

electron-pair delocalization

Answer 4

The process by which electron density is spread over several atoms rather than remaining between two.

Question 5

formal charge

Answer 5

The hypothetical charge on an atom in a molecule or ion, equal to the number of valence electrons minus the sum of all the unshared and half the shared valence electrons

Question 6

electron deficient

Answer 6

Referring to a bonded atom, such as Be or B, that has fewer than eight valence electrons

Question 7

free radical

Answer 7

A molecular or atomic species with one or more unpaired electrons which typically make it very reactive

Question 8

expanded valence shell

Answer 8

A valence level that can accommodate more than eight electrons by using available d orbitals; occurs only with central nonmetal atoms from Period 3 or higher

Question 9

VSEPR

Answer 9

A model explaining that the shapes of molecules and ions result from minimizing electron-pair repulsions around a central atom

Question 10

molecular shape

Answer 10

The three dimensional structure defined by the relative positions of the atomic nuclei in a molecule

Question 11

bond angle

Answer 11

The angle formed by the nuclei of two surrounding atoms with the nucleus of the central atom at the vertex

Question 12

linear arrangement

Answer 12

The geometric arrangement obtained when two electron groups maximize their separation around a central atom

Question 13

linear shape

Answer 13

A molecular shape formed by three atoms lying in straight line, with a bond angle of 180.

Question 14

trigonal planar arrangement

Answer 14

The geometric arrangement formed when three electron groups maximize their separation around a central atom

Question 15

bent shape

Answer 15

A molecular shape that arises when a central atom is bonded to two other atoms and has one or two lone pairs

Question 16

tetrahedral arrangement

Answer 16

The geometric arrangement formed when four electron groups maximize their separation around central atom; when all four groups are bonding groups, the molecular shape is tetrahedral

Question 17

trigonal pyramidal shape

Answer 17

A molecular shape caused by the presence of one lone pair in a tetrahedral arrangement

Question 18

trigonal bipyramidal arrangement

Answer 18

The geometric arrangement formed when five electron groups maximize their separation around a central atom

Question 19

equatorial group

Answer 19

An atom that lies in the trigonal plane of a trigonal bipyramidal molecule, or a similar structural feature in a molecule

Question 20

axial group

Answer 20

An atom that lies above or below the trigonal plane of a trigonal bipyramidal molecule, or a similar structural feature in a molecule

Question 21

seesaw shape

Answer 21

A molecular shape caused by the presence of one equatorial lone pair in a trigonal bipyramidal arrangement

Question 22

T shape

Answer 22

A molecular shape caused by the presence of two equatorial lone pairs in a trigonal bipyramidal arrangement

Question 23

octahedral arrangement

Answer 23

The geometric arrangement obtained when six electron groups maximize their space around central atom

Question 24

square pyramidal shape

Answer 24

A molecular shape caused by the presence of one lone pair in an octahedral arrangement

Question 25

square planar shape

Answer 25

A molecular shape caused by the presence of two lone pairs at opposite vertices in an octahedral arrangement

Question 26

molecular polarity

Answer 26

The overall distribution of electronic charge in a molecule, determined by its shape and bond polarities

Question 27

dipole moment

Answer 27

A measure of molecular polarity; the magnitude of the partial charges on the ends of a molecule times the distance between them