What is a characteristic feature of polar molecules?

Polar molecules are characterized by the presence of partial positive and negative charges due to the unequal sharing of electrons between the atoms involved in the bond. This unequal sharing occurs because of differences in electronegativity between the atoms, resulting in a dipole moment where one end of the molecule becomes slightly positive and the other end becomes slightly negative.

This feature of having partial charges is essential in determining the behavior of polar molecules in various conditions, including their interaction with other molecules. For instance, polar molecules are typically soluble in polar solvents due to their ability to interact through dipole-dipole interactions and hydrogen bonds, which is a fundamental principle in chemistry. The presence of these partial charges allows polar molecules to engage in various biochemical processes essential for life, such as the formation of cellular structures and the behavior of water.

In contrast, free-moving electrons are typically associated with metallic bonds, and a uniform distribution of charge characterizes non-polar molecules. Polar molecules are generally insoluble in non-polar solvents because they cannot effectively interact with non-polar molecules due to the lack of polarity, which prevents any significant interactions that would lead to solubility.