SCH 4C
Electronegativity and The Bonding Continuum
Electronegativity is a measure of an atom’s ability to attract the pair of electrons it shares with another
atom within a covalent bond. In general, metals have lower electronegativities than non-metals. Fluorine
has the highest electronegativity, 4.0. Therefore, it has the greatest ability to attract shared electrons.
Electronegativity values can be found on your periodic table.
Types of bonding can be determined by calculating the difference in electronegativities (EN) between
atoms in a bond. To calculate the EN subtract the electronegativity of one element from the other.
EN = higher EN – lower EN
0
Non-polar Covalent
0.5
1.7
Polar Covalent
Ionic Bond
When the EN is between:
0 - 0.5
the bond is non-polar covalent
0.6 – 1.6
the bond is polar covalent
1.7
the bond is ionic
For each of the following , calculate the EN value and classify the bonding as either non-polar covalent
(NP), polar covalent (P) or ionic (I).
a) BrCl
b) Cs2S
c) NaI
d) Br2
ENBr =
EN =
EN =
EN =
ENCl =
EN =
EN =
EN =
EN =
Bonding Type :
e) H2O
EN =
EN =
EN =
Bonding Type :
f) Cl2
EN =
EN =
EN =
Bonding Type :
g) H2S
ENBr =
ENCl =
EN =
Bonding Type :
h) MgCl2
EN =
EN =
EN =
Bonding Type :
i) CH4
EN =
EN =
EN =
Bonding Type :
j) CaO
EN =
EN =
EN =
Bonding Type :
k) CO2
EN =
EN =
EN =
Bonding Type :
l) CCl4
EN =
EN =
EN =
Bonding Type :
m) NH3
EN =
EN =
EN =
Bonding Type :
n) OCl2
EN =
EN =
EN =
Bonding Type :
o) HCl
EN =
EN =
EN =
Bonding Type :
p) N2
EN =
EN =
EN =
Bonding Type :
q) SiF4
EN =
EN =
EN =
Bonding Type :
r) Na2O
EN =
EN =
EN =
Bonding Type :
s) KBr
EN =
EN =
EN =
Bonding Type :
t) HI
EN =
EN =
EN =
Bonding Type :
EN =
Bonding Type :
EN =
Bonding Type :
EN =
Bonding Type :
Draw the appropriate Lewis structure for each of the compounds above. Remember, ionic compounds
are drawn as equations showing the formation of ions while covalent compounds are drawn with lines to
indicate 2 shared electrons.