As a liquid such as honey or water is warmed, what happens to its viscosity and its surface tension?

Core Concept

Viscosity and surface tension both originate from intermolecular attractions opposing molecular motion. Raising temperature raises average kinetic energy, so a larger fraction of molecules can slip past neighbors or leave the tightly knit surface. Warm honey pours rapidly and warm water spreads more readily than cold, showing both quantities falling together. Added heat never strengthens the underlying attractive forces, so neither property can rise with temperature.