Hydrogen bonds form when hydrogen bonds with which elements?

• A. Hydrogen bonds form when hydrogen bonds with fluorine.
• B. Hydrogen bonds form when hydrogen bonds with oxygen or nitrogen.
• C. Hydrogen bonds form when hydrogen bonds with fluorine, oxygen, or nitrogen.
• D. Hydrogen bonds are stronger than covalent bonds.

Answer: (C)

Hydrogen bonds form when a hydrogen atom that is covalently bonded to a highly electronegative atom is attracted to a lone pair on another electronegative atom. This creates a directional, relatively strong dipole–dipole interaction that characterizes hydrogen bonding. The common partners for this interaction are fluorine, oxygen, and nitrogen, so including all three reflects where these bonds can occur. Hydrogen bonds are weaker than covalent bonds, so describing them as stronger would be incorrect. Limiting the explanation to only fluorine or to only oxygen and nitrogen would miss valid hydrogen-bonding cases.