What property of water allows it to form hydrogen bonds?

Water's ability to form hydrogen bonds stems from its polar nature. Each water molecule has a bent shape, with a partial negative charge near the oxygen atom and a partial positive charge near the hydrogen atoms. This uneven distribution of electrical charge gives water its polarity.

The polar nature of water allows it to interact favorably with other polar molecules and ions, enabling hydrogen bonds to form. In a hydrogen bond, the positively charged hydrogen atom of one water molecule is attracted to the negatively charged oxygen atom of another water molecule. This interaction is critical for many of water's unique properties, including high surface tension, high heat capacity, and the ability to dissolve a wide range of substances.

Other options related to pH, nonpolar characteristics, or density do not accurately reflect the fundamental reason for hydrogen bonding in water. Thus, it is the polar nature of water that serves as the foundation for this important type of molecular interaction.