Hydrogen bonds are a type of Van der Waals interaction that specifically involve

• A. Metal atoms
• B. Ions
• C. Hydrogen and highly electronegative atoms such as oxygen or nitrogen
• D. Noble gas atoms

Answer: (C)

Hydrogen bonds form when a hydrogen atom that is covalently bonded to a highly electronegative atom becomes attracted to the lone pairs on another electronegative atom in a nearby molecule. The electronegative atom to which hydrogen is bonded (such as oxygen or nitrogen) pulls electron density away, giving hydrogen a partial positive charge. This polarized hydrogen then interacts electrostatically with a lone pair on another electronegative atom, creating a relatively strong, directional dipole-dipole interaction compared with typical van der Waals forces. This specific arrangement requires hydrogen and a highly electronegative partner like O or N, so it isn’t seen with metals, ions, or noble gas atoms, which either don’t provide the necessary polar H donor–acceptor setup or interact only through other, weaker forces. Hence, the statement that hydrogen bonds specifically involve hydrogen and highly electronegative atoms such as oxygen or nitrogen is the correct description.