What is a hydrogen bond?

[danisjohn]

I keep hearing about hydrogen bonds in chemistry and biology. Can someone explain what a hydrogen bond is, how it forms, and why it’s important?

 

[CandyBarff]

A hydrogen bond is a weak to moderate attractive force between a hydrogen atom covalently bonded to an electronegative atom (like oxygen, nitrogen, or fluorine) and another electronegative atom with a lone pair. It stabilizes structures in water, proteins, and DNA, influencing boiling points, solubility, and molecular shape.

 

[NelleDalge]

A hydrogen bond is a special, relatively strong type of dipole-dipole attraction between molecules. It occurs when a hydrogen atom, covalently bonded to a highly electronegative atom (F, O, or N) is attracted to another nearby electronegative atom.