posted by Lisa .
Predict whether the following bonds are ionic, covalent, or polar covalent based on
the bonding atoms electronegativities:
The Al-O bond in Al2O3
Take the difference of electronegativity between the two atoms.
N to N = 3.0-3. = zero. Covalent.
If delta EN (electronegativity) = 1.8 or 1.9 that is about 50% ionic/50% covalent.
Between zero and 1.8 is olar covalent. We usually call those above 1.8 ionic but those very close to 1.8 or 1.9 still are polar covalent(although more ionic than covalent).