In the space-filling model, what determines the relative sizes of the spheres?

Explanation:

A space-filling model is defined as a model that shows three-dimensional representation of a molecule.

This model is also known as Calotte model. In this type of model, atoms are represented as balls or spheres and bonds between the atoms are represented by sticks.

The radii of sphere are proportional to the radii of atoms.

Therefore, we can conclude that in the space-filling model, atomic radii determines the relative sizes of the spheres.