What best describes a hydrogen bond?

A hydrogen bond is best described as an attraction between a partially positive hydrogen atom and a partially negative atom, typically oxygen or nitrogen. This type of bond emerges when a hydrogen atom is covalently bonded to a more electronegative atom, such as oxygen in water molecules. The electronegative atom attracts the shared electrons more strongly, resulting in a polarity where the hydrogen becomes partially positive.

Hydrogen bonds are crucial in various biological processes, especially in maintaining the structure of proteins and nucleic acids, and they play a significant role in the unique properties of water, such as its high surface tension and specific heat capacity.

In contrast to covalent bonds, which involve the sharing of electrons, or ionic bonds that involve the complete transfer of electrons, hydrogen bonds are relatively weak and are based more on electrostatic attractions between molecules rather than specific atomic bonding.