B. Polarity of Bonds p.18
Difference in electronegativity can be used to determine how polar a bond is
between two atoms.
Difference in
electronegativity
Less than 0.2
Type of bonds
Electron sharing
Non-polar covalent
More or less equal
0.2-1.7
Polar covalent
Unequal
More than 1.7
Ionic
Electron gained and lost
For the following molecules, use the Table of Electronegativities to calculate the
electronegativity difference. Then, tell whether the bond is: non-polar covalent,
polar covalent or ionic. In addition, indicate which atom has the greater share of
the bonding electrons.
Formula
Electronegativity
difference
Type of bond
NO
N = 3.0
O = 3.5
EN = 0.5
Mg = 1.2
O = 3.5
EN = 2.3
Br = 2.8
EN = 0
Li = 1.0
H = 2.1
EN = 1.1
Li = 1.0
Br = 2.8
EN = 1.8
Cu = 1.9
F = 4.0
EN = 2.1
C = 2.5
O = 3.5
EN = 1.0
H = 2.1
At = 2.2
EN = 0.1
polar
covalent
ionic
MgO
Br2
LiH
LiBr
CuF
CO
HAt
Atom with
greater electron
share (-)
oxygen
oxygen
non polar
covalent
none
polar
covalent
ionic
hydrogen
ionic
fluoride
polar
covalent
non polar
covalent
oxygen
bromide
astatine