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calcium chloride

(Encyclopedia)calcium chloride, CaCl2, chemical compound that is crystalline, lumpy, or flaky, is usually white, and is very soluble in water. The anhydrous compound is hygroscopic; it rapidly absorbs water and is ...

Laurent, Auguste

(Encyclopedia)Laurent, Auguste ōgüstˈ lōräNˈ [key], 1808–53, French organic chemist. He devised a systematic nomenclature for organic chemistry. His studies on naphthalene and its chlorination products led ...

insecticides

(Encyclopedia)insecticides, chemical, biological, or other agents used to destroy insect pests; the term commonly refers to chemical agents only. The liabilities of chemical insecticides have encouraged interest ...

hyperinsulinism

(Encyclopedia)hyperinsulinism, presence in the system of an above-normal amount of insulin, the substance secreted by the pancreas and needed by the body to utilize sugar. An increased amount of insulin in the body...

ether, in chemistry

(Encyclopedia)CE5 Ethers ether, any of a number of organic compounds whose molecules contain two hydrocarbon groups joined by single bonds to an oxygen atom. The most common of these compounds is ethyl ether, C...

smaltite

(Encyclopedia)smaltite smôlˈtīt [key], opaque tin-white to steel-gray mineral of the pyrite group, a compound of cobalt and arsenic. It occurs in massive form, occasionally in crystals (cubes) of the isometric s...

photocopying

(Encyclopedia)photocopying, process whereby written or printed matter is directly copied by photographic techniques. Generally, photocopying is practical when just a few copies of an original are needed. When many ...

cobaltite

(Encyclopedia)cobaltite kōˈbôltīt, kōbôlˈtīt [key], opaque, silver-white, sometimes reddish or grayish mineral of the pyrite group, a compound of cobalt, arsenic, and sulfur, CoAsS. It occurs in crystals of...

ink

(Encyclopedia)ink, pigmented fluid used for writing and drawing, or a viscous compound used for printing, both of various colors but most frequently black. The oldest known variety, India ink or China ink, is still...

peroxide

(Encyclopedia)peroxide pərŏkˈsīd [key], chemical compound containing two oxygen atoms, each of which is bonded to the other and to a radical or some element other than oxygen; e.g., in hydrogen peroxide, H2O2, ...