Here's why:
* Space-filling models depict the atoms as spheres with radii proportional to their van der Waals radii. This accurately portrays the actual space occupied by the atoms in a molecule.
* Ball-and-stick models, while showing the bonds and angles, don't accurately represent the size of the atoms.
* Lewis structures only show the connectivity of atoms and electron pairs, neglecting the three-dimensional arrangement.
* Skeletal structures are simplified representations useful for understanding connectivity but lack any visual representation of the molecule's shape.
Therefore, space-filling models provide the most realistic and informative representation of a molecule's three-dimensional structure.
