Polar covalent bond

Definition

A polar covalent bond is a type of covalent bond where electrons are shared unequally between atoms, resulting in a dipole moment. This occurs because one atom has a higher electronegativity than the other.

5 Must Know Facts For Your Next Test

1. Polar covalent bonds occur between atoms with different electronegativities (usually between 0.4 and 1.7 difference).
2. The atom with the higher electronegativity gains a partial negative charge, while the other atom gains a partial positive charge.
3. Water (H₂O) is a common example of a molecule with polar covalent bonds.
4. Polar covalent bonds result in molecules having dipole moments, which affect their physical properties like boiling and melting points.
5. The unequal sharing of electrons can lead to molecular polarity, influencing solubility in various solvents.

Review Questions

• What causes the formation of a polar covalent bond?
• How does electronegativity difference relate to polar covalent bonding?
• Give an example of a molecule that has polar covalent bonds and explain its significance.

Related terms

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

Dipole Moment: A measure of the separation of positive and negative charges in a molecule due to unequal electron sharing.

Nonpolar Covalent Bond: A type of covalent bond where electrons are shared equally between two atoms, resulting in no significant charge separation.