The key difference between ball and stick and space filling model is that in the ball and stick model, the molecular structures are depicted by spheres and rods whereas, in the space-filling model, the molecular structures are depicted by full-sized spheres without rods.
We can use different molecular models to represent molecular structures as 3D structures. However, the ball and stick model is the most common structure among them. Besides, the space-filling model is also useful in different occasions.
CONTENTS
1. Overview and Key Difference
2. What is Space-Filling Model
3. What is Ball and Stick Model
4. Side by Side Comparison – Ball and Stick vs Space-Filling Model in Tabular Form
5. Summary
What is Ball and Stick Model?
Ball and stick model is a molecular model where we can display a molecule using spheres and rods. The spheres represent the atoms of the molecule and rods give the chemical bonds between the atoms. These are three-dimensional structures. We can also represent the double and triple bonds using this model. We have to use two rods between two spheres to show a double bond and three rods between two spheres to show a triple bond.
Moreover, we can represent the bond angles as well. We have to locate the bonds in the correct angle and correctly position the spheres measuring the centres of the spheres at the correct distance between them. Often, the colour of the sphere gives the chemical element of the atom.
Figure 01: Ball and stick model showing single bonds with one rod and double bond with two rods between two atoms (two spheres)
Besides these, the radius of the sphere has to be smaller than the length of the rod. In this way, it provides a clear view of the atoms and bonds between them. However, we cannot get a clear idea about the space occupied by the model.
What is Space Filling Model?
Space-filling model is a molecular model in which we can display a molecule using spheres. In difference to the ball and stick model, this model uses only spheres to represent atoms; there are no rods to represent chemical bonds between atoms. Instead, the spheres are full-sized. In this model, the radii of the spheres are proportional to the radii of the atoms.
Figure 02: Space-filling model shows the effective shape of the molecule
The centre-to-centre distances of spheres are also proportional to the distances between atomic nuclei. Moreover, we can display the atoms of different chemical elements using different colours to distinguish them from each other easily. Concerning the usefulness of this model; this type of molecular models is important in visualizing the effective shape of a molecule and the relative dimension of the molecule.
What is the Difference Between Ball and Stick and Space Filling Model?
Ball and stick model and space filling model are two common ways of representing the 3D structure of molecules. These two models are different from each other, depending on the way the chemical bonds are represented. The key difference between ball and stick and space filling model is that in the ball and stick model, the molecular structures are given using spheres and rods, whereas, in the space-filling model, the molecular structures are given as full-sized spheres without rods.
Furthermore, we can show double bonds, triple bonds, the bond angles, etc. using the ball and stick model, but in space filling model we can show the effective shape of the molecule and the relative dimension of the molecule. So, this is also a major difference between ball and stick and space filling model.
Summary – Ball and Stick vs Space Filling Model
Ball and stick model and space filling model are two common ways of representing the 3D structure of molecules. These two models are different from each other, depending on the way that the chemical bonds are represented. The key difference between ball and stick and space filling model is that, in the ball and stick model, the molecular structures are depicted by spheres and rods, whereas, in the space filling model, the molecular structures are depicted by full-sized spheres without rods.
Reference:
1. “Ball-and-Stick Model.” Wikipedia, Wikimedia Foundation, 9 Oct. 2019, Available here.
Image Courtesy:
1. “Acetone-3D-balls” By Ben Mills – Own work (Public Domain) via Commons Wikimedia
2. “Guanosine-diphosphate-anion-3D-spacefill” By Jynto (talk) – Own workThis image was created with Discovery Studio Visualizer (CC0) via Commons Wikimedia