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atomic clock

(Encyclopedia)atomic clock, electric or electronic timekeeping device that is controlled by atomic or molecular oscillations. A timekeeping device must contain or be connected to some apparatus that oscillates at a...

designer drug

(Encyclopedia)designer drug, chemical substance synthesized in a laboratory that is intended to have effects similar to those of a drug that is a controlled substance, such as methamphetamine, marijuana, LSD, or an...

CN (tear gas)

(Encyclopedia)CN, ordinary tear gas. The chemical name for CN is chloroacetophenone. ...

ilmenite

(Encyclopedia)ilmenite ĭlˈmĕnīt [key], black mineral, iron titanium oxide, FeTiO3, crystallizing in the hexagonal system. It is sometimes found as tabular hexagonal crystals but occurs more commonly as small gr...

Hartung, Hans

(Encyclopedia)Hartung, Hans häns härˈto͝ong [key], 1904–89, French painter, b. Germany. Hartung rejected the early influence of German expressionism and developed an entirely abstract style in which a strong ...

Boltwood, Bertram Borden

(Encyclopedia)Boltwood, Bertram Borden, 1870–1927, American chemist and physicist, b. Amherst, Mass., grad. Sheffield Scientific School, Yale, 1892. After graduate study at Leipzig and Yale (Ph.D., 1897), he taug...

Monroeville

(Encyclopedia)Monroeville, borough (1990 pop. 29,169), Allegheny co., SW Pa., a suburb of Pittsburgh; settled 1810, inc. 1952. It is primarily residential, with a major shopping mall. Monroeville has chemical and n...

Pople, Sir John Anthony

(Encyclopedia)Pople, Sir John Anthony pōpˈəl [key], 1925–2004, British computational chemist. Trained as a mathematician at Cambridge (B.A. 1946, Ph.D. 1951), he worked at Cambridge (1951–58) and England's N...

sulfur dioxide

(Encyclopedia)sulfur dioxide, chemical compound, SO2, a colorless gas with a pungent, suffocating odor. It is readily soluble in cold water, sparingly soluble in hot water, and soluble in alcohol, acetic acid, and ...

lithium

(Encyclopedia)lithium lĭthˈēəm [key] [Gr.,=stone], metallic chemical element; symbol Li; at. no. 3; interval in which at. wt. ranges 6.938–6.997; m.p. about 180.54℃; b.p. about 1,342℃; sp. gr. .534 at 20�...