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PART II
CovalentBonds
LET’SFIRSTREVIEWIONICBONDING
In an IONIC bond,electrons are lost or gained,resulting in the formation of IONS
in ionic compounds.
FK
FK
FK
FK
FK
FK
FK
FK+ _
FK+ _
The compound potassium fluorideconsists of potassium (K+) ions
and fluoride (F-) ions
FK+ _
The ionic bond is the attractionbetween the positive K+ ion
and the negative F- ion
Sowhatarecovalentbonds?
In covalent bonding,atoms still want to achievea noble gas configuration(the octet rule).
In covalent bonding,atoms still want to achievea noble gas configuration(the octet rule).
But rather than losing or gainingelectrons,atoms now share an electron pair.
In covalent bonding,atoms still want to achievea noble gas configuration(the octet rule).
But rather than losing or gainingelectrons,atoms now share an electron pair.
The shared electron pairis called a bonding pair
Cl2
Chlorineforms
acovalent
bondwithitself
ClClHowwilltwochlorineatomsreact?
ClClEach chlorine atom wants to gain one electron to achieve an octet
ClClNeither atom will give up an electron –chlorine is highly electronegative.
What’s the solution – what can theydo to achieve an octet?
ClCl
Cl Cl
Cl Cl
Cl Cl
Cl Cloctet
Cl Cl
circle the electrons foreach atom that completestheir octets
octet
Cl Cl
circle the electrons foreach atom that completestheir octets
The octet is achieved byeach atom sharing theelectron pair in the middle
Cl Cl
circle the electrons foreach atom that completestheir octets
The octet is achieved byeach atom sharing theelectron pair in the middle
Cl Cl
circle the electrons foreach atom that completestheir octets
This is the bonding pair
Cl Cl
circle the electrons foreach atom that completestheir octets
It is a single bonding pair
Cl Cl
circle the electrons foreach atom that completestheir octets
It is called a SINGLE BOND
Cl Cl
circle the electrons foreach atom that completestheir octets
Single bonds are abbreviatedwith a dash
Cl Cl
circle the electrons foreach atom that completestheir octets
This is the chlorine molecule,
Cl2
O2
Oxygen is also one of the diatomic molecules
How will two oxygen atoms bond?
OO
OOEach atom has two unpaired electrons
OO
OO
OO
OO
OO
OO
Oxygen atoms are highly electronegative.
So both atoms want to gain two electrons.
OO
Oxygen atoms are highly electronegative.
So both atoms want to gain two electrons.
OO
OO
OO
OO
OO
OOBoth electron pairs are shared.
6 valence electronsplus 2 shared electrons
= full octet
OO
6 valence electronsplus 2 shared electrons
= full octet
OO
two bonding pairs,
OOmaking a double bond
OO=For convenience, the double bond
can be shown as two dashes.
OO
OO=This is the oxygen molecule,
O2
this is so
cool!!
