In a sample of water H2O , the primary type of intermolecular force present is hydrogen bonding. Hydrogen bonding is a strong type of dipole-dipole interaction that occurs when a hydrogen atom is bonded to a highly electronegative atom such as oxygen, nitrogen, or fluorine and is attracted to another electronegative atom.In a sample of methane CH4 , the primary type of intermolecular force present is London dispersion forces, also known as van der Waals forces. These are weak, temporary attractions between instantaneous dipoles that form due to the random movement of electrons in the molecule.Comparing the strength of these intermolecular forces, hydrogen bonding in water is significantly stronger than the London dispersion forces in methane. This difference in strength is responsible for the higher boiling and melting points of water compared to methane, as well as water's higher heat capacity and surface tension.