Final answer:
The VSEPR model is used to predict the molecular geometry by arranging electron pairs as far apart as possible to minimize repulsions, resulting in the lowest energy arrangement.
Step-by-step explanation:
When using the VSEPR model, the preferred arrangement of electron pairs around a central atom in a molecule or polyatomic ion is the one that minimizes electron pair repulsions. This theory operates under the principle that electron groups, whether they are in bonds or as lone pairs, will repel each other.
Thus, electrons and electron groups are arranged as far apart as possible around the central atom to minimize these repulsions, leading to various molecular geometries such as linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral structures depending on the number of electron groups involved.
The VSEPR model is often used to predict the three-dimensional structures of compounds. Although it simplifies the complex interactions in a molecule, it effectively predicts the structure by using the concept of minimizing electron pair repulsions to determine the most stable geometry with the lowest potential energy.