Different styles of visualizing molecules in 3D exist. The following 3D Structures show Glucose in the four most common visualization styles. Click/tap and drag molecules to rotate them.

In the Wire model bonds are represented by lines. Atoms are located at corners or end of lines. As you can see, this model is generally not well suited, as it is hard to see. It is often used to show geometries of unimportant parts of molecules not in focus of the visualization.

In the Sticks model bonds are represented by cylinders. Like in the wire models, atoms are located at the end of these cylinders or at corners and atom types are indicated by color. This model is much more suited for visualization of molecules. However, it is not as commonly used as the next.

In the Sticks & Balls model atoms are indicated by balls while bonds are sticks. As before, atom types are indicated by their color. This is the preferred visualization of many chemists, as it allows us to esily identify the 3D structure.

In the Space Filling model (calotte model) atoms are represented as balls with radii proportional to the radii of the atoms involved. Often the Van der Waals radius is used. These models are great for grasping the overall shape of molecule, however, they make it difficult to identify the structure and connectivity between atoms. However, it is to note that the Space Filling model is only a rough approximation to the actual shape of the molecule. To gain a more realistic view of the shape of the molecule we can use an electron density isosurface:

In this digital textbook, we will be mostly using the Sticks & Balls model.