Chemistry

Van der Waals forces (London dispersion, dipole–dipole, and hydrogen bonding in some contexts) are all weak interactions arising from temporary or permanent partial charges. Ion–dipole forces and true hydrogen bonding are fundamentally stronger because they involve a full formal charge (the ion) or an exceptionally polarized $\ce{H}$ atom bonded to highly electronegative atoms like $\ce{N}$, $\ce{O}$, or $\ce{F}$. The key insight is that strength determines classification: when an interaction is strong enough to dominate molecular behavior, it gets its own category rather than being lumped with weaker, more universal forces.

Van der Waals forces (London dispersion, dipole–dipole, and hydrogen bonding in some contexts) are all weak interactions arising from temporary or permanent partial charges. Ion–dipole forces and true hydrogen bonding are fundamentally stronger because they involve a full formal charge (the ion) or an exceptionally polarized $\ce{H}$ atom bonded to highly electronegative atoms like $\ce{N}$, $\ce{O}$, or $\ce{F}$. The key insight is that strength determines classification: when an interaction is strong enough to dominate molecular behavior, it gets its own category rather than being lumped with weaker, more universal forces.