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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...

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...

sneeze gas

(Encyclopedia)sneeze gas, poison gas used in riot control and chemical warfare. It is highly irritating to the nose and throat; inhalation of the substance causes sneezing and coughing, but rarely causes permanent ...

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 ...

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...

East Chicago

(Encyclopedia)East Chicago, city (2020 pop. 26,370), Lake co., extreme NW Ind., on Lake Michigan, in the industrialized Calumet region, ad...

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...

Polanyi, John Charles

(Encyclopedia)Polanyi, John Charles, 1929–, Canadian chemist. Raised and educated in England, he worked as a researcher in Canada before taking a teaching position at the Univ. of Toronto in 1956. He used spectro...

Prince George

(Encyclopedia)Prince George, city (1991 pop. 69,653), central British Columbia, Canada, at the confluence of the Fraser and Nechako rivers. It is a railroad division point and a distribution center for a lumber reg...