Columbia Encyclopedia

Search results

428 results found

grease

(Encyclopedia)grease, mixture of lubricant and thickener. It is used to reduce friction between surfaces from which oils would leak away or cause damage by dripping, or where lubrication must be assured for extende...

blackbody

(Encyclopedia)blackbody, in physics, an ideal black substance that absorbs all and reflects none of the radiant energy falling on it. Lampblack, or powdered carbon, which reflects less than 2% of the radiation fall...

iron

(Encyclopedia)iron, metallic chemical element; symbol Fe [Lat. ferrum]; at. no. 26; at. wt. 55.845; m.p. about 1,535℃; b.p. about 2,750℃; sp. gr. 7.87 at 20℃; valence +2, +3, +4, or +6. Iron is biologically s...

chlorate

(Encyclopedia)chlorate pərklōrˈāt, –klôrˈ– [key], salts of chloric acid, HClO3, and perchloric acid, HClO4, respectively. Perchlorates are safer to handle than chlorates; they are more stable when expos...

Libby, Willard Frank

(Encyclopedia)Libby, Willard Frank, 1908–80, American chemist, b. Grand Valley, Colo., grad. Univ. of California (B.S., 1931; Ph.D., 1933). He taught (1933–45) at the Univ. of California and was a chemist (1941...

Schrock, Richard Royce

(Encyclopedia)Schrock, Richard Royce, 1945–, American chemist, b. Berne, Ind., Ph.D Harvard, 1971. After working for three years with the Dupont Company, he became (1972) a professor at the Massachusetts Institut...

Nernst, Walther Hermann

(Encyclopedia)Nernst, Walther Hermann välˈtər hĕrˈmän nĕrnst [key], 1864–1941, German physicist and chemist, a founder of modern physical chemistry. After doing outstanding research on osmotic pressure and...

mercaptan

(Encyclopedia)mercaptan thīˈōl [key], any of a class of organic compounds containing the group –SH bonded to a carbon atom. The volatile low-molecular-weight mercaptans have disagreeable odors. Mercaptans are ...

mass number

(Encyclopedia)mass number, often represented by the symbol A, the total number of nucleons (neutrons and protons) in the nucleus of an atom. All atoms of a chemical element have the same atomic number (number of pr...

Chauvin, Yves

(Encyclopedia)Chauvin, Yves, 1930–2015, French chemist, b. Menen, Belgium, grad. Lyon School of Chemistry, Physics, and Electronics (CPE), 1954. Chauvin was a research engineer (1960–91) and then research direc...