Chemistry Reference
In-Depth Information
Fig. 6.13 Hexagonal and cubic close-packing as models of different metal structures [
17
]
Na
+
-Ion
Li
+
-Ion
O
2
-
-Ion
Cl
-
-Ion
Zn
2
+
-Ion
Na
+
-Ion
S
2
-
-Ion
Cl
-
-Ion
Fig. 6.14 Cubic-close-packing as models for salt crystal structures [
18
]
sphere packings easily when they have the opportunity to produce these models
themselves by stacking spheres. With M6.1-M6.7 (see the “modeling course” at
the end of this chapter) the building of sphere packings is suggested for the labora-
tory. Further information on metal structures can be found elsewhere (see also [
5
]
or [
17
]).
If the holes in the cubic close-packing of spheres are introduced, one obtains the
sodium chloride structure by filling out the octahedral holes with small balls (see
Fig.
6.14
). If the tetrahedral holes are being filled, the lithium oxide structure
results. The zinc sulfide structure results in case that only half of the tetrahedral
holes are filled. The construction of these salt structures is suggested for the lab with
M6.8-M6.15 (see end of this chapter, also [
5
]or[
18
]).
Molecular models
. As soon as gases are to be interpreted with the structure-
oriented approach, the structures of appropriate molecules are to be demonstrated
