Determining Polarity of a Compound

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Polar & Non-Polar Compounds

To determine polarity we look at the electronegativity differences between individuals bonds between atoms and then at the compound as a whole. Note that we can have a molecule where individual bonds are polar but overall the molecule is non-polar.

Key Ideas about Polarity

  • Polarity is based on a difference in electronegativity between atoms.
  • When the electronegativity difference is less than 0.5, we say the bond is nonpolar.
  • Between 0.5 and 2.0 is considered polar.
  • Over 2.0 is considered ionic.
  • BUT … in a molecule it is possible the polar bonds cancel each other and result in a nonpolar molecule. We must consider symmetry.

This simulation from PhET will let you get a "feel" for Polarity. It maybe work best to visit their simulation directly for a larger version.



More Help and Practice




Polarity of H2O Water Molecule Showing Postivie and Negative Areas

The difference in electronegativites between Hydrogen (white atoms) and Oxygen (red) results in a postivie area (around the H atoms) and negative area (around the O). Therefore the molecule is polar.