What does molecular polarity mean?
Molecular polarity refers to a permanent dipole arising from an uneven distribution of electric charge. Bond polarity matters, but is not sufficient by itself. Three-dimensional geometry determines whether individual bond dipoles cancel.
From bonds to the whole molecule
Electronegativity differences can make bonded atoms attract electrons unequally. In bent water molecules, bond dipoles do not cancel, whereas the equal opposing dipoles in linear carbon dioxide can cancel. Polar bonds therefore do not guarantee a polar molecule. Geometry must account for electron pairs and actual spatial arrangement, not just lines in a flat drawing.
Solubility and interactions
Polarity influences intermolecular interactions and solvent choice. Like dissolves like is a useful guide, not a universal law: ionization, hydrogen bonding, temperature, and entropy also matter. Some molecules contain both water-interacting and oil-interacting regions, a feature important in detergents. Polarity alone does not determine whether a substance is safe or harmful.