crystal systems
81Azobenzene — Azobenzene …
82axis — axis1 axised /ak sist/, adj. /ak sis/, n., pl. axes /ak seez/. 1. the line about which a rotating body, such as the earth, turns. 2. Math. a. a central line that bisects a two dimensional body or figure. b. a line about which a three dimensional… …
83melting point — Physical Chem. the temperature at which a solid substance melts or fuses. [1835 45] * * * Temperature at which the solid and liquid states of a pure substance can exist in equilibrium. As heat is applied to a solid, its temperature increases… …
84form — formable, adj. formably, adv. /fawrm/, n. 1. external appearance of a clearly defined area, as distinguished from color or material; configuration: a triangular form. 2. the shape of a thing or person. 3. a body, esp. that of a human being. 4. a… …
85hexagonal system — ▪ crystallography one of the principal categories of structures to which a given crystalline solid can be assigned. Components of crystals in this system are located by reference to four axes three of equal lengths set at 120° to one… …
86isometric system — ▪ crystallography also called Cubic System, one of the crystal systems to which a given crystalline solid can be assigned. Crystals in this system are referred to three mutually perpendicular axes of equal lengths. If the atoms or atom… …
87Amphibole — (pronounced amfi bowl) defines an important group of generally dark colored rock forming inosilicate minerals, composed of double chain SiO4 tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their… …
88Hermann-Mauguin notation — is used to represent the symmetry elements in point groups, plane groups and space groups. It is named after the German crystallographer Carl Hermann and the French minerologist Charles Victor Mauguin. This notation is sometimes called… …
89Christian Samuel Weiss — (February 26, 1780 October 1, 1856) was a German mineralogist born in Leipzig. After graduation he was a physics instructor in Leipzig from 1803 until 1808. In 1810 he became a professor of mineralogy at the University of Berlin. Weiss is… …
90Molecular symmetry — in chemistry describes the symmetry present in molecules and the classification of molecules according to their symmetry. Molecular symmetry is a fundamental concept in chemistry, as it can predict or explain many of a molecule s chemical… …
