But two H atoms or two H2 molecules undergo dipole-dipole dispersive interactions without having permanent dipoles. Likewise for two orientation-averaged H2O molecules. What's the magnitude of a typical hydrogen bond? Can it be measured in any or all phases of H2O?
I have heard this statement before but I have no idea what it means. I think I know what dipole-dipole interactions are but I'm not sure about their relation to hydrogen bonds and conversely. Could you please elaborate?