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Flashcards in Chapter 10 Deck (27):
1

Lewis Structure

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

2

resonance structure

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

3

resonance hybrid

The weighted average of the resonance structures of a molecule

4

electron-pair delocalization

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

5

formal charge

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

6

electron deficient

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

7

free radical

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

8

expanded valence shell

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

9

VSEPR

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

10

molecular shape

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

11

bond angle

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

12

linear arrangement

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

13

linear shape

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

14

trigonal planar arrangement

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

15

bent shape

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

16

tetrahedral arrangement

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

17

trigonal pyramidal shape

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

18

trigonal bipyramidal arrangement

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

19

equatorial group

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

20

axial group

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

21

seesaw shape

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

22

T shape

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

23

octahedral arrangement

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

24

square pyramidal shape

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

25

square planar shape

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

26

molecular polarity

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

27

dipole moment

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