Keesom force

Keesom force, also known as dipole-dipole interaction, is a type of weak attraction between molecules that have permanent electric dipoles—meaning, parts of the molecule have a slight positive or negative charge consistently. These positive and negative regions are attracted to opposite charges in neighboring molecules, creating an intermolecular force. Think of it as tiny magnets within molecules pulling them slightly together. Keesom forces are significant in determining the properties of polar substances, such as their boiling points and states of matter, but they are generally weaker than covalent or ionic bonds.