What is meant by polar molecules and what are non-polar molecules?

Polar molecules have uneven charge distribution (positive & negative ends); non-polar have even charge distribution.

• A polar molecule has a net dipole moment due to differences in electronegativity and shape (example: H₂O).
• Non-polar molecules have symmetrical charge or equal sharing (example: O₂, N₂, CO₂ (linear) ).
• Polarity affects solubility, boiling point, interactions, etc.