Check the chemical formula for metal + nonmetal
Identify whether the bond is ionic, polar covalent, or nonpolar covalent
Compare electronegativity values of the bonded atoms
Larger electronegativity difference indicates greater polarity
The more electronegative atom is the negative end
The less electronegative atom is the positive end
For molecules, determine the shape using VSEPR
Check whether bond dipoles cancel out
Symmetrical molecules with identical outer atoms are often nonpolar
Asymmetrical molecules with polar bonds are often polar
Look for lone pairs on the central atom
Lone pairs often increase molecular polarity
For ions, use the sign of the charge to identify polarity
For acids and bases, identify the ionizable hydrogen or charged group
Use a periodic table electronegativity trend if exact values are unavailable