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fluorine

(Encyclopedia)fluorine flo͞oˈərēn, –rĭn [key], gaseous chemical element; symbol F; at. no. 9; at. wt. 18.9984; m.p. −219.6℃; b.p. −188.14℃; density 1.696 grams per liter at STP; valence −1. Fluorin...

Semyonov, Nikolay Nikolayevich

(Encyclopedia)Semyonov, Nikolay Nikolayevich, or Nikolai Nikolaevic Semenov, 1896–1986, Soviet physical chemist, Ph.D. Petrograd Univ., 1917. Semyonov was a professor at the Leningrad Physico-Technical Institute ...

kurchatovium

(Encyclopedia)kurchatovium kûrˌchətōˈvēəm [key], symbol Ku, former suggested name for element 104, now called rutherfordium. ...

joliotium

(Encyclopedia)joliotium zhōlyōˈshēəm [key], symbol Jl, former suggested name for element 105, now called dubnium. ...

Breviary of Alaric

(Encyclopedia)Breviary of Alaric ăˈlərĭk [key], Visigothic code of Roman law issued (506) by King Alaric II for his Roman subjects in Spain and S Gaul. It is also known as the Lex Romana Visigothorum. Based lar...

Río

(Encyclopedia)Río and Rio, respectively Spanish and Portuguese terms for river. For those not listed here, see under the second element of the name. Thus, for Río Lerma, see Lerma. ...

International Union of Pure and Applied Chemistry

(Encyclopedia)International Union of Pure and Applied Chemistry (IUPAC), an international organization est. 1919 to advance the chemical sciences and contribute to the application of chemistry to the service of hum...

molecule

(Encyclopedia)molecule mŏlˈəkyo͞ol [key] [New Lat.,=little mass], smallest particle of a compound that has all the chemical properties of that compound. A single atom is usually not referred to as a molecule, a...

chloride

(Encyclopedia)chloride klōrˈīd, klôrˈ– [key], chemical compound containing chlorine. Most chlorides are salts that are formed either by direct union of chlorine with a metal or by reaction of hydrochloric ac...

ozone

(Encyclopedia)ozone ōˈzōn [key], an allotropic form of the chemical element oxygen (see allotropy). Pure ozone is an unstable, faintly bluish gas with a characteristic fresh, penetrating odor. The gas has a dens...