Polar molecule

Definition

A polar molecule has an uneven distribution of electron density, resulting in regions with partial positive and negative charges. This occurs due to differences in electronegativity between atoms within the molecule.

5 Must Know Facts For Your Next Test

1. Polar molecules have a net dipole moment due to the asymmetric arrangement of polar bonds.
2. Water (H₂O) is a classic example of a polar molecule because of its bent shape and the difference in electronegativity between hydrogen and oxygen.
3. The polarity of a molecule affects its physical properties such as boiling point, melting point, and solubility.
4. In a polar bond, electrons are shared unequally between atoms, leading to partial charges on each atom.
5. Polarity influences intermolecular forces like hydrogen bonding, which is crucial for understanding molecular interactions.

Review Questions

• What characteristic defines a polar molecule?
• How does the shape of a molecule influence its polarity?
• Why is water considered a polar molecule?

Related terms

Electronegativity: A measure of an atom's ability to attract and hold onto electrons within a chemical bond.

Dipole Moment: A measure of the separation of positive and negative charges in a molecule; it indicates the polarity of the molecule.

Intermolecular Forces: Forces that occur between molecules, influencing their physical properties. Examples include hydrogen bonding, dipole-dipole interactions, and London dispersion forces.