Slide 1 : Covalent
Bonds
Slide 2 : LET’S
FIRST
REVIEW
IONIC
BONDING
Slide 3 : In an IONIC bond,
electrons are lost or gained,
resulting in the formation of IONS
in ionic compounds.
Slide 4 : F K
Slide 5 : F K
Slide 6 : F K
Slide 7 : F K
Slide 8 : F K
Slide 9 : F K
Slide 10 : F K
Slide 11 : F K The compound potassium fluoride
consists of potassium (K+) ions
and fluoride (F-) ions
Slide 12 : F K + _ The ionic bond is the attraction
between the positive K+ ion
and the negative F- ion
Slide 13 : So
what
are
covalent
bonds?
Slide 14 : In covalent bonding,
atoms still want to achieve
a noble gas configuration
(the octet rule).
Slide 15 : In covalent bonding,
atoms still want to achieve
a noble gas configuration
(the octet rule). But rather than losing or gaining
electrons,
atoms now share an electron pair.
Slide 16 : In covalent bonding,
atoms still want to achieve
a noble gas configuration
(the octet rule). But rather than losing or gaining
electrons,
atoms now share an electron pair. The shared electron pair
is called a bonding pair
Slide 17 : Cl2 Chlorine
forms
a
covalent
bond
with
itself
Slide 18 : Cl Cl How
will
two
chlorine
atoms
react?
Slide 19 : Cl Cl Each chlorine atom wants to
gain one electron to achieve an octet
Slide 20 : Cl Cl Neither atom will give up an electron –
chlorine is highly electronegative. What’s the solution – what can they
do to achieve an octet?
Slide 21 : Cl Cl
Slide 22 :
Slide 23 : Cl Cl
Slide 24 : Cl Cl
Slide 25 : Cl Cl octet
Slide 26 : Cl Cl circle the electrons for
each atom that completes
their octets octet
Slide 27 : Cl Cl circle the electrons for
each atom that completes
their octets The octet is achieved by
each atom sharing the
electron pair in the middle
Slide 28 : Cl Cl circle the electrons for
each atom that completes
their octets The octet is achieved by
each atom sharing the
electron pair in the middle
Slide 29 : Cl Cl circle the electrons for
each atom that completes
their octets This is the bonding pair
Slide 30 : Cl Cl circle the electrons for
each atom that completes
their octets It is a single bonding pair
Slide 31 : Cl Cl circle the electrons for
each atom that completes
their octets It is called a SINGLE BOND
Slide 32 : Cl Cl circle the electrons for
each atom that completes
their octets Single bonds are abbreviated
with a dash
Slide 33 : Cl Cl circle the electrons for
each atom that completes
their octets This is the chlorine molecule,
Cl2
Slide 34 : O2 Oxygen is also one of the diatomic molecules
Slide 35 : How will two oxygen atoms bond?
Slide 36 : Each atom has two unpaired electrons
Slide 37 :
Slide 38 :
Slide 39 :
Slide 40 :
Slide 41 :
Slide 42 :
Slide 43 : Oxygen atoms are highly electronegative. So both atoms want to gain two electrons.
Slide 44 : Oxygen atoms are highly electronegative. So both atoms want to gain two electrons.
Slide 45 :
Slide 46 :
Slide 47 :
Slide 48 :
Slide 49 : O O Both electron pairs are shared.
Slide 50 : 6 valence electrons
plus 2 shared electrons
= full octet O O
Slide 51 : 6 valence electrons
plus 2 shared electrons
= full octet O O
Slide 52 : two bonding pairs, O O making a double bond
Slide 53 : For convenience, the double bond
can be shown as two dashes.
Slide 54 : This is the oxygen molecule,
O2
Slide 55 : Covalent bonding allows for
an amazingly large variety
of compounds such as
Slide 56 : small compounds like
water and carbon dioxide,
Slide 57 : and ethanol (alcohol),
Slide 58 : to larger compounds
such as aspirin, (21 atoms)
Slide 59 : and the
sex hormones estradiol
(estrogen)
and
testosterone, (49 atoms) (44 atoms)
Slide 60 : to all of the 40,000 proteins
you have in your body,
including
Slide 61 : insulin,
with 779 atoms,
Slide 62 : and hemoglobin,
with about 11,000 atoms!
Slide 63 : There are an estimated
1040 possible compounds
containing up to 50 atoms The known chemical world,
including natural and
synthetic compounds,
is far far far below 1% of that. NATURE volume 442 p. 502 3 August 2006
Slide 64 : As of 2007, there are about
31,000,000 known compounds; CAS registry: http://www.cas.org/cgi-bin/regreport.pl About 12.5 million of those
are commercially available. Thousands of new compounds
are discovered or synthesized
every week!