Columbia Encyclopedia

Search results

500 results found

americium

(Encyclopedia)americium ămərĭˈshēəm [key], artificially produced radioactive chemical element; symbol Am; at. no. 95; mass no. of most stable isotope 243; m.p. about 1,175℃; b.p. about 2,600℃; sp. gr. 13....

iridium

(Encyclopedia)iridium ĭrĭdˈēəm [key], metallic chemical element; symbol Ir; at. no. 77; at. wt. 192.217; m.p. about 2,410℃; b.p. about 4,130℃; sp. gr. 22.55 at 20℃; valence +3 or +4. Iridium is a very ha...

hafnium

(Encyclopedia)hafnium hăfˈnēəm [key], metallic chemical element; symbol Hf; at. no. 72; at. wt. 178.49; m.p. about 2,227℃; b.p. 4,602℃; sp. gr. 13.31 at 20℃; valence +4. Hafnium is a lustrous, ductile, si...

cadmium

(Encyclopedia)cadmium kădˈmēəm [key] [from cadmia, Lat. for calamine, with which cadmium is found associated], metallic chemical element; symbol Cd; at. no. 48; at. wt. 112.411; m.p. 321℃; b.p. 765℃; sp. gr...

carbonyl group

(Encyclopedia)carbonyl group kärˈbənĭl [key], in chemistry, functional group that consists of an oxygen atom joined by a double bond to a carbon atom. The carbon atom is joined to the remainder of the molecule ...

biochemistry

(Encyclopedia)biochemistry, science concerned chiefly with the chemistry of biological processes; it attempts to utilize the tools and concepts of chemistry, particularly organic and physical chemistry, for elucida...

spectrum

(Encyclopedia)CE5 Dispersion of white light by a triangular prism spectrum, arrangement or display of light or other form of radiation separated according to wavelength, frequency, energy, or some other propert...

Mulliken, Robert Sanderson

(Encyclopedia)Mulliken, Robert Sanderson, 1896–1986, American chemist, b. Newburyport, Mass., Ph.D. Univ. of Chicago, 1921. Mulliken taught at New York Univ. from 1926 to 1928 and then at the Univ. of Chicago fro...

Maribor

(Encyclopedia)Maribor mäˈrĭbôr [key], Ger. Marburg, city (1991 pop. 103,961), in Slovenia, on the Drava River. It is a heavy industrial center with chemical, engineering, and electrical industries. Known as ear...

Kursk

(Encyclopedia)Kursk ko͝orsk [key], city (1989 pop. 424,000), capital of Kursk region, W European Russia, at the confluence of the Tuskor and Seim rivers. An important rail junction, it has machine, chemical, and s...