Polar compounds are molecules that have a significant difference in electronegativity between their atoms, leading to an uneven distribution of electrical charge. This results in a partial positive charge on one end of the molecule and a partial negative charge on the other, creating a dipole moment. Common examples of polar compounds include water, ammonia, and hydrochloric acid. Due to their polar nature, these compounds tend to dissolve well in polar solvents, such as water, and are often involved in various chemical reactions. Their polarity also influences their physical properties, such as boiling and melting points, making them distinct from nonpolar compounds, which do not have a dipole moment.