Which type of bond is responsible for the attraction between a hydrogen atom and a more electronegative atom in a molecule?

• A. Ionic bond
• B. Covalent bond
• C. Hydrogen bond
• D. Polar covalent bond

Answer: (C)

Hydrogen bonds arise when a hydrogen atom that is covalently bonded to a strongly electronegative atom (like oxygen, nitrogen, or fluorine) carries a partial positive charge. That positively polarized hydrogen can be attracted to lone pairs on a nearby electronegative atom, creating an electrostatic attraction called a hydrogen bond. This interaction is weaker than covalent or ionic bonds but plays a crucial role in the behavior of water, DNA, and many biomolecules. It’s distinct from covalent bonds (which share electrons within a molecule) and ionic bonds (which involve electron transfer to form ions), and it’s different from a polar covalent bond, which is simply a covalent bond with unequal sharing inside the same bond rather than an intermolecular attraction.