ABSTRACT
In addition to the symbols for fundamental constants given in Table 3, a number of other symbols and abbreviations are to be found in the text. These are:
5 entropy H enthalpy (heat content) K equilibrium constant ccp cubic close-packed hep hexagonal close-packed bcc body-centred cube m or m.p. melts or melting point b or b.p. boils or boiling point d decomposes subi sublimes
: The naming of geometrical shapes Since the geometry of solids was first worked out by the ancient Greeks, much of the terminology comes from Greek and occasionally causes misunderstanding. A regular solid is named for the number of faces, and the Greek root is hedron. Thus the tetrahedron is named for its four faces. The plural is formed by turning -ron into -ra, and similarly for the adjective. Thus 'tetrahedra' is the plural and 'tetrahedral' the adjective. Since we normally deal with atoms arranged in a geometrical form around a central atom, the chemist is usually more interested in the number of points or vertices (note the singular is vertex) in a figure, rather than the number of faces. While a tetrahedron has four points and four faces, the number of points and faces differs for all other solids. Thus an octahedron, familiar as the shape found for 6-coordination, has eight faces (hence octa-) and six vertices.
