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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...

San Marcos, University of

(Encyclopedia)San Marcos, University of, at Lima, Peru; the first university in South America; founded 1551 by the Spanish king Charles I (Holy Roman Emperor Charles V) and recognized by papal bull in 1571; closed ...

Rauma

(Encyclopedia)Rauma rouˈmä [key], Swed. Raumo, city (1996 pop. 37,914), Western Finland prov., SW Finland, on the Gulf of Bothnia. It is Finland's leading western port and has wood, paper, chemical, leather, muni...

tear gas

(Encyclopedia)tear gas, gas that causes temporary blindness through the excessive flow of tears resulting from irritation of the eyes. The gas is used in chemical warfare and as a means for dispersing mobs. Compoun...

tissue culture

(Encyclopedia)tissue culture, the propagation of plants through the placement of small amounts of undifferentiated tissue or single cells in an artificial environment. The tissue is placed in a nutrient medium that...