Salt Model: Pre-Built Structure
Show the crystal structure of salt (NaCl) with this pre-built polyhedral model of one unit cell. Or emphasize closest-packed layers by standing the cubic unit cell on one corner. The Salt Model comes in three layers that can easily be stacked one atop the other to form a NaCl unit cell. If the layers are connected, the model can be used in two orientations (as illustrated in graphics):
- Unit cell: When the model is resting on one face of the cube, the cubic shape of the unit cell is evident.
- Closest-packed Layers: When the model is balanced on a single octahedron, the closest-packed layers are evident.
The salt model illustrates that most simple inorganic compounds consist of ions that alternate indefinitely rather than existing as discrete molecules in the solid state. Although the formula NaCl shows a one-to-one ratio of ions, a salt crystal does not consist of just one sodium ion and just one chloride ion. Rather, in NaCl each sodium ion is surrounded by an octahedron of chloride ions and each chloride ion is surrounded by an octahedron of sodium ions in an extended structure.
Salt has been designed and adapted by ICE using octahedral units from the Polyhedral Model Kit. The Polyhedral Model Kit was produced by University of Wisconsin–Madison Materials Research Science and Engineering Center (MRSEC) and is distributed by ICE. The Solid State Model Kit provides an alternative view of the salt structure.