1. VI. Polarity

2. A. Polarity
The bonding pairs of electrons in covalent bonds are pulled by the nuclei

3. A. Polarity Cont.
Electronegativity values determine the charge distribution in a covalent bond
electronegativity: a measure of an atom’s attraction for electrons

4. B. Nonpolar Covalent Bond
Bond between two nonmetal atoms with the same (or extremely close) electronegativity.
Bonded electrons are shared equally
Ex: H2, O2, N2

5. C. Polar Covalent Bond
Bond between 2 nonmetal atoms with different electronegativity values.
Bonded electrons are shared unequally.
Atom with higher electronegativity pulls more strongly and has a partial negative charge
Atom with lower electronegativity pulls less strongly and has a partial positive charge

6. D. Polar Molecules
In a polar molecule, one end of the molecule is slightly negative and the other end is slightly positive.
A molecule that has two poles (opposite charges) is called a dipolar molecule, or dipole.

7. E. Determining Polar/Nonpolar/Ionic
Use difference in electronegativity values to determine the type of bond.
Difference
Type of Bond
0.0 – 0.4
Nonpolar covalent
0.4 – 1.0
Moderately polar covalent
1.0 – 2.0
Very polar covalent
≥ 2.0
Ionic

8. Example #1 Determine the type of bond between H and Cl.
H = 2.1 Cl = 3.0

9. H and Br C and O Br and Br K and Cl P and F Example 2
H = 2.1 Br = 3.0 C = 2.5 O = 3.5 K = 0.8
Cl = 3.0 P = 2.1 F = 4.0
H and Br
C and O
Br and Br
K and Cl
P and F