Molecular models are used to represent the three-dimensional structure of molecules and to show the arrangement of atoms within them. Space-filling models show the relative sizes of the atoms, and ball-and-stick models show the bonds between the atoms. Models can help to visualize the electronic structure of molecules and to understand the relationship between a molecule's structure and its properties. They can also be used to predict the reactivity of molecules and to design new compounds with specific properties.

In addition to showing the arrangement of atoms, molecular models can also be used to show the following qualities of a compound and chemical structure:

- Bond lengths

- Bond angles

- Dihedral angles

- Symmetry

- Molecular orbitals

- Electron density

Molecular models are an important tool in the study of chemistry and can help to provide a better understanding of the structure and properties of compounds.