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dysprosium

(Encyclopedia)dysprosium dĭsprōˈzēəm [key] [Gr.,=hard to get at], metallic chemical element; symbol Dy; at. no. 66; at. wt. 162.500; m.p. 1,412℃; b.p. 2,562℃; sp. gr. 8.54 at 25℃; valence+3. Dysprosium i...

einsteinium

(Encyclopedia)einsteinium īnˈstīˌnēəm, īnstīˈ– [key] [for Albert Einstein], artificially produced radioactive chemical element; symbol Es; at. no. 99; mass no. of most stable isotope 252; m.p. about 860�...

silica

(Encyclopedia)silica or silicon dioxide, chemical compound, SiO2. It is insoluble in water, slightly soluble in alkalies, and soluble in dilute hydrofluoric acid. Pure silica is colorless to white. It occurs in sev...

ytterbium

(Encyclopedia)ytterbium ĭtûrˈbēəm [key] [for Ytterby, a town in Sweden], metallic chemical element; symbol Yb; at. no. 70; at. wt. 173.054; m.p. 819℃; b.p. about 1,194℃; sp. gr. about 7.0; valence +2 or +3...

isotope

(Encyclopedia)CE5 Isotopes of hydrogen isotope īˈsətōp [key], in chemistry and physics, one of two or more atoms having the same atomic number but differing in atomic weight and mass number. The concept of ...

periodic table

(Encyclopedia)CE5 periodic table, chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arrange...

Lipscomb, William Nunn, Jr.

(Encyclopedia)Lipscomb, William Nunn, Jr. lĭpˈskəm [key], 1919–2011, American physical chemist, b. Cleveland, Ph.D. California Institute of Technology, 1946. A professor of chemistry at the Univ. of Minnesota ...

mechanism

(Encyclopedia)mechanism, philosophical theory about the nature of organic systems, holding that organisms are machines in the sense that they are material systems. Mechanism seeks to explain biological processes, i...

lead acetate

(Encyclopedia)lead acetate, chemical compound, a white crystalline substance with a sweetish taste. Like other lead compounds, it is very poisonous. Lead acetate is soluble in water and glycerin. With water it form...

Rustavi

(Encyclopedia)Rustavi ro͝ostäˈvē [key], city (1989 pop. 153,661), E Georgia, on the Kura River. It was an industrial center, with ironworks and steelworks and chemical plants, but the local economy collapsed in...