Examples of dominating van der Waals forces

Van der Waals forces are present in everything that contains electrons, which is just about everything! They are short-lived forces that act between molecules and even single atoms! Despite being short-lived, they can still account for all the states of matter, causing, for instance, iodine to be solid and oil to be liquid at room temperature.

Van der Waals forces are strong between large molecules

Between large molecules, Van der Waals dispersion forces are especially prominent because of their large electron clouds. As a result, large molecules are often liquids, or even solids, at room temperature. Oil, for instance, is made from very long chain-like molecules and is, therefore, a liquid. Another example is graphite, the dark grey substance inside a pencil. Between graphite's large but thin carbon layers, van der Waals forces dominate. The layers can slide relative to each other, which is why graphite is a soft solid that we can easily transfer to paper through a gentle push.

Fun fact! Van der Waals dispersion forces are also how spiders and geckos traverse up walls and on ceilings.

Figure 1: The structure of graphite. Within the layers of graphite, carbon atoms bond covalently to each other. These layers stack on top of each other with the help of van der Waals dispersion forces.