This is a collection of thirteen models of crystal lattices suitable for display in the classroom. The models are made of painted wooden balls connected with wire.
Curriculum Notes
These models are useful whenever specific crystal geometries or even just the crystalline nature of solids are being discussed. These models can be passed around the classroom. This demo can take as much or as little time as you want.
One day of lead time is required for this project.
Discussion
Most solids exist in crystalline form such that their particles (atoms, ions, or molecules) are arranged in a regularly extended three-dimensional lattice. All textbooks are somewhat limited in that their representations of these lattices are perforce two-dimensional. These models really help some students to grasp the three-dimensional nature of crystal lattices.
Materials
You may choose any or all of the following models:
- calcium carbonate (calcite - rhombohedral)
- sodium sulfate (octahedral)
- zinc sulfide (hexagonal) X3
- aluminum (face-centered cubic)
- magnesium (hexagonal close-packed)
- sodium chloride
- cadmium chloride
- carbon dioxide
- calcium titanite
- carbon (diamond)
- a generic triclinic crystal
Procedure
Display the models in any way that fits your curriculum.
Safety Precautions
Don't drop them on your toe!