Valence Shell
Electrons
Electron Repulsion Theory USER
repel each other
Valence é pairs will arrange such that they minimize their
mutual repulsion
maximize the distance from each other
Predicting VSEPR
1 Stene
of lone pair
t
bonding pairs attached
to central atom
2 Electron pair geometry
3 Molecular geometry I consider the atoms that are
central atom
Deriving VSEPR Theory Molecular Shape
Elecotrons
will
situate in 3D Space so that
they
are not
close to each other
Consider the geometry about a central atom
Steric
SNI
of central atom which is equal to
of atomsbonded
Thisgives the
overall shape
lonepairs
t E P G ofthe
of
molecule
ble both
egoism
at
consider everything
on central atom
bonded
to the
Two types
l Electron
of geometries
pair
Geometry Relative positions of all lone pairs
bonding pairs attached to the central atom
EPG
should always be one of the 5
2 Molecular Geometry
common shapes of molecules
Position of
atoms
bonds
your molecules
bonded to
Central atoms
Polarity
E of
dipoles
in
Dipoles
vectors
that lie
of
across bono
t show the
distribution of e
E
of dipoles
polarity
Polarity how are molecule behaves in a magnetic
field It molecule aligns polar
Polarity E of dipoles drawn for bonds in molecules
t it polar have a permanent dipole left over
from adding together dipole
moments
Shortcut If
youhave unbalanced lone pairs
Molecule
Valence Bond
Theory
Explains molecular bonding
Hybrid
Polar
Orbitals
at the atomic level
Premise A bond is formed when orbitals Overlap
Ex H2
Mis
t
I
n
ti ti
B o
HF
His
His
f
f
M
I
Hybridization
overlap Bond
11
Yes
H
Fister
n estetra
a
mixing of atomic
new bonding sets called
of lobes
of orbitals
need to hybridize to
Cases where not
Ex
to make
hybrid orbidals
shape geometry
tells us how
The steric
In between
orbitals
we
make the geometry
d bond
internuclear axis
orbitals need
all
many orbitals
to be hybridized
Haq
a
p
C
H
11 17
LS
Oif
p
Mtsspzsf
Ozo foxtails
H
I
c
c u
2P
is
l D
off Ji
2mi
is is
lie
Titi
is is
I
SP
is is
r
Is
is
Is
r
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Shortcut
SN
For Hybridization
of hybrid
SN 2
SN 3
SN 4
SN 5
SNIG
Additionally
orbit as
Ex
SP
SP
É
Sp
SP'd
I
Spd
for
I single bond
Acrolein
M
o
O bonds
M Abonus L
9AM centralatoms
are SN 3 which
H Means SP
tf bonds
10 bond
I Double Bond lo t t t bond
I Triple Bono lot 21T bonds
is