Molecular Geometry

bent, 120

2 BP and 1 LP

linear, 180

2 BP and 3 LP

octahedral, 90

6 BP

see-saw, 90 and 120

4 BP and 1 LP

square planar, 90 and 180

4 BP and 2 LP

square pyramidal, 90 and 180

5 BP and 1 LP

tetrahedral, 109.5

4 BP

Bent, 109.5

2 BP and 2 LP

trigonal bipyramidal, 90 and 120

5 BP

trigonal planar, 120

3 BP

trigonal pyramidal, 109.5

3 BP and 1 LP

t-shaped, 90 and 180

3 BP and 2 LP

109.5

Tetrahedral Angle

120

Angle between bonds in trigonal planar geometry

90

Angle between bonds in Octahedral Geometry

Pairs of electrons arrange themselves so as to have the maximum distance between them and their neighbors. Model for predicting geometry.

VSEPR

Bonded Pair

2 electrons shared by two atoms

Lone Pair

2 electrons on an atom that are not involved in a bond; takes up more space than a bonded pair

Single Bond

2 shared electrons; bond order of 1

Double Bond

4 shared electrons; bond order of 2

Triple Bond

6 shared electrons; bond order of 3

Octet Rule

Atoms will share electrons so that they have 8 electrons in their outer shell (to achieve noble gas configuration)

Resonance

When a molecule can have two or more equivalent structures, usually with different arrangement of double bonds

electron deficient

atoms that can have less than an octet; B and Be

expanded octet

atoms that can have more than an octet; must be in 3rd period and below on periodic table

formal charge (on an atom)

# valence electrons from P.T. - # electrons assigned to the atom in the Lewis structure; lower formal charges usually indicate "better" lewis structures

anion

negative ion; has additional electrons

cation

positive ion; has fewer electrons