Covalent Bond
- Chemical bonding involving non-metals only.
- Chemical bond formed by the sharing of at least a pair of
electrons between two atoms to obtain an octet.
- The degree of sharing depends on the value of electronegativity
for each atom. The bigger the value of electronegativity, the
greater the tendency of an atom to attract a shared pair of
electrons.
- Electronegativity increases as you go across and up the Periodic
Table.
- A pure covalent bond results when you have equal sharing of
electrons. The electronegativity values are the same for each
atom, i.e. diatomic molecules.
- A polar covalent bond results when you have unequal sharing of
electrons.
- You can use the bonding continuum to indicate the degree of
polarity.
Type of Bond
100%
covalent
Difference in
Electronegativity
0
Slightly
Very
Polar
100%
polar
polar
Ionic
covalent
Ionic
covalent
covalent
0.5
0.6
1.6
1.7
- If the electronegativity difference is = to or > 1.6, then the
bond is ionic or has ionic properties.
- If the electronegativity difference is < 1.6, then the bond has
some degree of covalent properties.
To Do:
- Show the formation of covalent bonds in the following
combinations. Indicate if the bonds formed are pure or polar
covalent, as well include the appropriate dipoles.
Cl and Cl
Br and Br
Ne and Ne
N and N
H and O
P and P
H and F
Cl and O
B and N
C and O
F and F
I and I
O and O
H and Cl
S and S
N and N
H and Ne
H and N
B and Cl
Si and Cl