Hydrogen bonding

Hydrogen bonding is a special type of strong dipole-dipole intermolecular force that occurs when a hydrogen atom, already bonded to a highly electronegative atom (like nitrogen, oxygen, or fluorine), is attracted to another highly electronegative atom in a different molecule or in the same large molecule.

This interaction is stronger than typical dipole-dipole forces due to the large electronegativity difference, which creates a significant partial positive charge on the hydrogen atom and a significant partial negative charge on the electronegative atom. It plays a crucial role in the properties of water, DNA, and proteins.

For example, in water ($\text{H}_2\text{O}$), the hydrogen atoms are bonded to oxygen. A hydrogen atom from one water molecule can form a hydrogen bond with the oxygen atom of an adjacent water molecule.