optically active substance
51polarimetry — See polarimetric. * * * ▪ chemistry in analytic chemistry, measurement of the angle of rotation of the plane of polarized light (that is, a beam of light in which the vibrations of the electromagnetic waves are confined to one plane) that… …
52rotation — 1. Turning or movement of a body around its axis. 2. A recurrence in regular order of certain events, such as the symptoms of a periodic disease. 3. In medical education, a period of time on a particular service or specialty …
53law — 1. A principle or rule. 2. A statement of fact detailing a sequence or relation of phenomena that is invariable under given conditions. SEE ALSO: principle, rule, theorem. [A.S. lagu] Alexander l. states that a jerky nystagmus becomes worse when… …
54optical activity — Physical Chem. the ability of a substance to rotate the plane of polarization of plane polarized light. [1875 80] * * * Ability of a substance to rotate the plane of polarization of a beam of light passed through it, either as crystals or in… …
55materials science — the study of the characteristics and uses of various materials, as glass, plastics, and metals. [1960 65] * * * Study of the properties of solid materials and how those properties are determined by the material s composition and structure, both… …
56liquid crystal — a liquid having certain crystalline characteristics, esp. different optical properties in different directions when exposed to an electric field. [1890 95] * * * Substance that flows like a liquid but maintains some of the ordered structure… …
57rare-earth element — /rair errth /, Chem. any of a group of closely related metallic elements, comprising the lanthanides, scandium, and yttrium, that are chemically similar by virtue of having the same number of valence electrons. Also called rare earth metal. [1955 …
58crystal — A solid of regular shape and, for a given compound, characteristic angles, formed when an element or compound solidifies slowly enough, as a result either of freezing from the liquid form or of precipitating out of solution, to allow the… …
59Hermann Emil Fischer — Infobox Scientist name = Emil Fischer image size = 180px caption = Hermann Emil Fischer birth date = birth date|1852|10|9|df=y birth place = Euskirchen, Germany nationality = Germany death date = death date and age|df=yes|1919|7|15|1852|10|9… …
60Ephedra (genus) — This article is about the genus Ephedra. For the use of the plant in medicine, see Ephedra. Ephedra Ephedra fragilis in Mallorca …
