What is the key factor in determining the strength of Van der Waals forces between molecules?

The strength of Van der Waals forces is intricately tied to the electron distribution within molecules. Electron distribution serves as the orchestrator, influencing the spontaneous formation of induced dipoles. When temporary fluctuations in electron distribution occur, they give rise to instantaneous dipoles in molecules, setting the stage for attractive interactions. The degree and extent of electron distribution directly impact the frequency and magnitude of these induced dipoles. This interplay becomes a determining factor in the overall strength of Van der Waals forces within molecular systems. Molecules with more extensive and dynamic electron distributions are prone to engage in a greater number of induced dipoles, fostering stronger attractive interactions.