Molecular polarity refers to the distribution of electrical charge within a molecule. It occurs when there is an uneven sharing of electrons between atoms, often due to differences in their electronegativity. This results in one end of the molecule becoming slightly negative and the other end slightly positive, creating a dipole moment. The polarity of a molecule affects its physical properties, such as boiling and melting points, solubility, and interactions with other molecules. For example, polar molecules, like water, tend to dissolve well in other polar substances, while nonpolar molecules, like oil, do not mix with polar solvents.