1. Using electro negativity values to find bond type

2. Electronegativity
The attraction of an atom for Shared electrons is called its electronegativity.
Fluorine has the greatest electronegativity.
The metals have low electronegativities.

3. Chemical Bonding: The Covalent Bond Model cont’d
Fig. 5.11
Abbreviated periodic table showing Pauling electronegativity values for selected representative elements.

5. Electronegativity
Electronegativity: a measure an atom’s attraction for the electrons it shares in a chemical bond with another atom
on the Pauling scale, fluorine, the most electronegative element is assigned a value of 4.0, and all other elements are assigned values relative to fluorine

6. Glossary Terms
nonpolar covalent bond: a covalent bond in which the electrons are shared equally by the two atoms
polar covalent bond (polar bond): a covalent bond between atoms in which the electrons are shared unequally
polar molecule: a molecule in which one side of the molecule is slightly negative and the opposite side is slightly positive

7. Finding bond type
Non-Polar covalent to polar covalent to Ionic to

8. Sample Problem 8.3
Identifying Bond Type
Which type of bond (nonpolar covalent, moderately polar covalent, very polar covalent, or ionic) will form between each of the following pairs of atoms?
a. N and H
b. F and F
c. Ca and Cl
d. Al and Cl

9. Solve Apply concepts to this problem.
Sample Problem 8.3
Solve Apply concepts to this problem. 2
Identify the electronegativities of each atom using Table 6.2.
a. N(3.0), H(2.1)
b. F(4.0), F(4.0)
c. Ca(1.0), Cl(3.0)
d. Al(1.5), Cl(3.0)

10. Solve Apply concepts to this problem.
Sample Problem 8.3
Solve Apply concepts to this problem. 2
Calculate the electronegativity difference between the two atoms.
The electronegativity difference between two atoms is expressed as the absolute value. So, you will never express the difference as a negative number.
a. N(3.0), H(2.1); 0.9
b. F(4.0), F(4.0); 0.0
c. Ca(1.0), Cl(3.0); 2.0
d. Al(1.5), Cl(3.0); 1.5

11. Solve Apply concepts to this problem.
Sample Problem 8.3
Solve Apply concepts to this problem. 2
Based on the electronegativity difference, determine the bond type using Table 8.4.
a. N(3.0), H(2.1); 0.9; moderately polar covalent
b. F(4.0), F(4.0); 0.0; nonpolar covalent
c. Ca(1.0), Cl(3.0); 2.0; ionic
d. Al(1.5), Cl(3.0); 1.5; very polar covalent