Which type of inter-molecular fprce occurs between all molecules?

The type of intermolecular force that occurs between all molecules is called London dispersion forces, or van der Waals forces. These forces arise from temporary fluctuations in electron density that create instantaneous dipoles, leading to attractions between neighboring molecules. Although they are typically weak compared to other intermolecular forces, such as hydrogen bonds and dipole-dipole interactions, they are universal and present in all substances, regardless of their polarity.