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Euler-Chelpin, Hans Karl August Simon von

(Encyclopedia)Euler-Chelpin, Hans Karl August Simon von, 1873–1964, Swedish biochemist, b. Germany, Ph.D. Univ. of Berlin, 1895. He spent his entire career at Stockholm Univ., first as professor and later as dire...

alkyne

(Encyclopedia)CE5 Alkynes alkyne ălˈkīn [key], any of a group of aliphatic hydrocarbons whose molecules contain one or more carbon-carbon triple bonds (see chemical bond). Alkynes with one triple bond have t...

californium

(Encyclopedia)californium kălˈĭfôrˌnēəm [key] [from California], artificially produced, radioactive metallic chemical element; symbol Cf; at. no. 98; mass no. of most stable isotope 251; m.p. about 900℃; b...

water

(Encyclopedia)CE5 A. Water molecule (black circles represent valence-shell electrons) B. Structure of ice: Each oxygen atom (white circles) is bonded to four other oxygen atoms by hydrogen bonds, the hydrogen at...

trinitrotoluene

(Encyclopedia)trinitrotoluene or TNT trīˌnīˌtrōtŏlˈyo͞oēn [key], CH3C6H2(NO2)3, crystalline, aromatic compound that melts at 81℃. It is prepared by the nitration of toluene. Trinitrotoluene is a high exp...

agrimony

(Encyclopedia)agrimony ăgˈrĭmōˌnē [key], any plant of the genus Agrimonia, perennials of the family Rosaceae (rose family) native to north temperate zones, to Brazil, and to Africa. They are found wild in the...

Fourcroy, Antoine François, comte de

(Encyclopedia)Fourcroy, Antoine François, comte de äNtwänˈ fräNswäˈ kôNt də fo͞orkrwäˈ [key], 1755–1809, French chemist. He was a pioneer in animal and plant chemistry and collaborated with Lavoisier ...

combining weight

(Encyclopedia)combining weight, the proportion (by weight) in which a chemical element combines with other elements to form compounds. The determination of combining weights was a very important part of early chemi...

Norrish, Ronald George Wreyford

(Encyclopedia)Norrish, Ronald George Wreyford, 1897–1978, British chemist, Ph.D. Cambridge, 1925. He joined the faculty at Cambridge in 1925 and was a professor there until he retired in 1965. Norrish was awarded...

nitro group

(Encyclopedia)nitro group, in chemistry, functional group that consists of a nitrogen atom joined to two oxygen atoms. Compounds that contain a nitro group, e.g., picric acid and trinitrotoluene (TNT), are called n...