What is the primary feature of hydrogen bonding?

The primary feature of hydrogen bonding is that it specifically requires highly electronegative atoms such as oxygen, nitrogen, or fluorine to interact with hydrogen. In a hydrogen bond, the hydrogen atom covalently bonded to a highly electronegative atom carries a partial positive charge due to the unequal sharing of electrons. This makes hydrogen attracted to the lone pair of electrons on another electronegative atom, creating a dipole-dipole interaction.

This characteristic is essential to many of the unique properties of water and biological molecules, including proteins and nucleic acids, where hydrogen bonds provide critical stabilization and influence molecular behavior. The specificity of the electronegative atoms involved is what distinguishes hydrogen bonding from other types of interactions.