Final answer:
The VSEPR model is used to predict molecular shapes based on the repulsion between electron pairs in the valence shell, but it doesn't give information on bond lengths or multiple bonds.
Step-by-step explanation:
The Valence-Shell Electron-Pair Repulsion (VSEPR) model is used to predict the shapes of molecules and polyatomic ions. It assesses the spatial relationships of atoms within a molecule based on the idea that electron pairs within the valence shell will repel each other to minimize their interactions.
According to the VSEPR theory, these repulsions dictate the geometry of the molecule, resulting in specific shapes that keep these electron pairs as far apart as possible. The Lewis electron-pair approach complements this by predicting the number and types of bonds, indicating which atoms have lone pairs of electrons but not their spatial arrangement. Therefore, combining the VSEPR model with the Lewis approach allows for a comprehensive understanding of molecular geometry. While helpful, the VSEPR model does not provide information on bond lengths or the presence of multiple bonds.