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semiconductor

(Encyclopedia)CE5 N-type and P-type crystals: In a pure silicon crystal each silicon atom (Si) is surrounded by four valence electrons. In the N-doped semiconductor, illustrated in the left-hand figure, some sil...

Kopp, Hermann Franz Moritz

(Encyclopedia)Kopp, Hermann Franz Moritz hĕrˈmän fräntz mōˈrĭts kôp [key], 1817–92, German physical chemist and historian of chemistry. His research concerned the connection between the physical propertie...

Soddy, Frederick

(Encyclopedia)Soddy, Frederick sŏdˈē [key], 1877–1956, English chemist. He worked under Lord Rutherford at McGill Univ. and with Sir William Ramsay at the Univ. of London. After serving (1910–14) as lecturer...

Corey, Elias James

(Encyclopedia)Corey, Elias James, 1928–, American organic chemist and educator, b. Methuen, Mass., grad. Massachusetts Institute of Technology (B.S. 1948, Ph.D. 1951). He has taught at the Univ. of Illinois (1951...

Dauphiné

(Encyclopedia)Dauphiné dōfēnāˈ [key], region and former province, SE France, bordering on Italy. It is now divided into three departments, Haute-Alpes, Isère, and Drôme. In the east the Alps culminate in the...

moscovium

(Encyclopedia)moscovium mŏskōˈvēəm [key], artificially produced radioactive chemical element; symbol Mc; at. no. 115; mass number of most stable isotope 288; m.p., b.p., sp. gr., and valence unknown. Situated ...

Ernst, Richard Robert

(Encyclopedia)Ernst, Richard Robert 1933–2021, Swiss chemist, Swiss Federal Institute of Technology Zurich (ETH Zurich; B.S., 1956, Ph.D., 1962). He worked as a res...

march, in music

(Encyclopedia)march, in music, composition intended to accompany marching. The only constant characteristics of a march are duple meter and a fairly simple rhythmic design. In mood, marches range from the moving de...

abacus, in architecture

(Encyclopedia)abacus ăbˈəkəs [key], in architecture, flat slab forming the top member of a capital. In classical orders it varies from a square form having unmolded sides in the Greek Doric, to thinner proporti...

Cassiopeia, in astronomy

(Encyclopedia)Cassiopeia, in astronomy, prominent northern constellation located almost directly opposite the Big Dipper across the north celestial pole. Five bright stars in the constellation form a rough W (or M)...