1. What is the role of electronegativity?
Bonding
What is the role of electronegativity?

2. Nuclei can pull on another atom’s electrons.
Nuclei in a tug of war
Nuclei can pull on another atom’s electrons.

3. Character determined by difference in electronegativities.
Bond character
Bonds are on a sliding scale from nonpolar covalent to ionic.

4. Equal electronegativity values = equal pull on the electrons
Nuclei in a tug of war
Nonpolar covalent bonds

5. Unequal electronegativity values = unequal pull on the electrons
Nuclei in a tug of war
Polar covalent bonds

6. Hugely unequal electronegativity values = essentially a transfer of electrons
Nuclei in a tug of war
Ionic bonds

7. Electron densities
Bond character
Note the equal, unequal and hugely unequal sharing of eletrons.