Columbia Encyclopedia

Search results

500 results found

executors and administrators

(Encyclopedia)executors and administrators. An executor is the person designated in the will of a deceased person to carry out the provisions of the will. An administrator is the person appointed by a probate court...

catalyst

(Encyclopedia)catalyst, substance that can cause a change in the rate of a chemical reaction without itself being consumed in the reaction; the changing of the reaction rate by use of a catalyst is called catalysis...

absorption

(Encyclopedia)absorption [Lat.,=sucking from], taking of molecules of one substance directly into another substance. It is contrasted with adsorption, in which the molecules adhere only to the surface of the second...

molecular modeling

(Encyclopedia)molecular modeling, the computer simulation, by various means, of chemical structures or processes. Special computer-graphics programs can display three-dimensional images of molecular structures and ...

geochemistry

(Encyclopedia)geochemistry, study of the chemical changes on the earth. More specifically, it is the study of the absolute and relative abundances of chemical elements in the minerals, soils, ores, rocks, water, an...

Leuna

(Encyclopedia)Leuna loiˈnä [key], city (1994 pop. 8,130), Saxony-Anhalt, S central Germany. There, in 1916, the first synthetic nitrogen plant began to operate after the invention of the Haber process. The city w...

Apted, Michael David

(Encyclopedia)Apted, Michael David, 1941-2021, British filmmaker, b. Aylesbury, Bucks, England. Apted began his career as a documentary filmmaker, beginning with the television program, Seven Up!, docum...

Bergman, Torbern Olof

(Encyclopedia)Bergman, Torbern Olof to͝orˈbərn o͞oˈlôv bĕrˈyəmän [key], 1735–84, Swedish chemist, physicist, and mineralogist. A professor at the Univ. of Uppsala from 1758, he developed a theory of che...

Calvin, Melvin

(Encyclopedia)Calvin, Melvin, 1911–97, American organic chemist and educator, b. St. Paul, Minn., grad. Michigan College of Mining and Technology, 1931, Ph.D. Univ. of Minnesota, 1935. In 1937 he joined the facul...

Cornforth, Sir John Warcup

(Encyclopedia)Cornforth, Sir John Warcup wôrˈkəp côrnˈfərth [key], 1917–2013, Australian chemist, Ph.D. Oxford, 1941. Although Cornforth suffered a hearing loss from childhood and was deaf by the time he gr...