Which of the following best defines a polar molecule?

A polar molecule is defined by having an uneven charge distribution due to unequal sharing of electrons among its constituent atoms. This occurs when there are significant differences in electronegativity between the atoms involved in a bond, resulting in polar covalent bonds.

In such a bond, the more electronegative atom attracts the shared electrons more strongly, leading to a partial negative charge on that atom and a partial positive charge on the less electronegative atom. This separation of charge within the molecule creates a dipole moment, making the molecule polar.

Polar molecules often exhibit specific properties, such as higher boiling and melting points and the ability to dissolve other polar substances or ionic compounds due to their dipole interactions. The correct identification of a polar molecule as one with an uneven charge distribution helps in understanding various chemical behaviors and interactions, such as solubility and reactivity with other compounds.

Other options presented do not accurately capture the essence of polarity. A molecule with equal sharing of electrons or a symmetrical charge distribution would not be polar, while the statement about a molecule that only interacts with non-polar solvents fails to encompass the broader nature of polar molecules.