B. Polarity of Bonds p.11
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 from page 3 to
calculate the electronegativity difference. Then, tell whether the bond is: nonpolar 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