Chemical Bonding
union between atoms
Charge separation
Transfer of electrons
No charge separation
Electrons shared between atoms
Opposites attract
δ+
δ–
Polar
Pure
covalent
covalent
bond
made
made
upofnonmetal
nonmetal
atoms
atoms
sharing
sharing
electrons
with
with
nonmetal
nonmetal
atoms
atoms
Metallic
Ionic
bond
bond
- metal
-bond
metal
cations
ionsup
and
in
aofnonmetal
sea
of (mobile)
anions
bonded
electrons
inelectrons
a 3D array
called
a crystal
lattice
• ionic
Unequal
sharing
oftogether
electrons
gives by
riseelectrostatic
to partial
charges;
positive
δ++]and
negative
Equalbonds
sharing
electrons
between
two
atoms;
electrons
shared
equally
metals
conduct
are of
electricity
held
tightly
ion chargens;
[M
attracts
[X– ] δ–
• the
bond
line (—)
represents
the sharing
two,
: , eletrons
of two,
:being
, electrons
shared;
(H :X)
(X:X) (H:H)
+______>
metals
ionic
substances
conduct
heat;
are
usually
(hot as found
well
asascold)
brittle
solids.
•Classic
both
the
more
atoms
have the
atom
electronegativities
has
theand
greatest
and
pullshare
on
electrons
sharedinto
(X:X)
electrons
(H:H)
(H :X)
equally
unequally
metals
Example:
areelectronegative
ductile
table
(tosame
draw
salt,
into
NaCl
wire)
malleable
(tothe
hammer
sheets)
Classic Examples: stomach
the sevenacid,
diatomic
H—Cl,
molecules
the waterHmolecule
—H
2, N2, O2,HF—O
2, Cl
2 Br2, I2
Physical Bonding
attractions between molecules
Chemical bond (___)
versus
Physical attraction (||||||||||||||)
δ+
δ–
δ+
δ–
Dispersion
forces
are
the weakest
attractive
forces
between
all molecules
hydrogen
bonding
- attractive
strongest
attractive
force
between
IF the following is met:
dipole ||||||||| dipole
- an
force
between
the
poles
ofmolecules,
polar
molecules
ONLY
intermolecular
observed
bybetween
nonpolar
molecules
is the
• molecule
X
= bond
N
O
F dispersive forces
athe
solid
linemust
(—)have
representsforce
a chemical
atoms
gray circle
a nonpolar
spherical
container
ofO—H
evenlymolecules
dispersed
• athe
hydrogen
must
be”attached
to X
N—H
F—H electrons
hashed
line
“represents
|||||||||
represents
anasattractive
force
between
polar
+] show
+]“attracts
nonpolar
molecules
little
between
•X
mustcharges;
have
an [δ
available
electron
pair
: ” : N—H
:+]O—H
: –F—H
partial
attracts
[δ– or
]|||||||||no
[δattraction
[δ– ]||||||||| [δnonpolar
attractsmolecules
[δ
]||||||||| [δ+]
Examples:
theasseven
diatomic
molecules
H2,|||||||||||
NH—Cl
O2, F|||||||||||
, I2: X—H
•Classic
bonding
is represent
hash
mark
“|||||||||||
” |||||||||: H—Cl
N—H
: F—H
Classic
example:
H—Cl
|||||||||
H—Cl
|||||||||
H—Cl
|||||||||
2:,O—H
2, Cl
2 Br2|||||||||||
Classic examples: water H2O, ammonia NH3, hydrofluoric acid HF
1