intermolecular forces
Thermal Expansion The intermolecular forces in liquids are strong enough to keep them from expanding significantly when heated typically only a few percent over a 100C temperature range . Thus the volumes of liquids are somewhat fixed. Notice from Table 11.1 "The Density of Water at Various Temperatures" that the density of water, for example, changes by only about 3% over a 90-degree temperature range. Table 11.1 The Density of Water at Various Temperatures.