Columbia Encyclopedia

Search results

500 results found

Tsien, Roger Yonchien

(Encyclopedia)Tsien, Roger Yonchien, 1952–2016, American biochemist, b. New York City, Ph.D. Cambridge, 1977. Tsien was a researcher at Cambridge (1977–81) and a professor at the Univ. of California, Berkeley (...

In

(Encyclopedia)In, symbol for the element indium. ...

dissociation

(Encyclopedia)dissociation, in chemistry, separation of a substance into atoms or ions. Thermal dissociation occurs at high temperatures. For example, hydrogen molecules (H2) dissociate into atoms (H) at very high ...

aqua regia

(Encyclopedia)aqua regia rēˈjēə [key] [Lat.,=royal water], corrosive, fuming yellow liquid prepared by mixing one volume of concentrated nitric acid with three to four volumes of concentrated hydrochloric acid....

ionization

(Encyclopedia)ionization: see ion.

pH

(Encyclopedia)pH, range of numbers expressing the relative acidity or alkalinity of a solution. In general, pH values range from 0 to 14. The pH of a neutral solution, i.e., one which is neither acidic nor alkaline...

ligand

(Encyclopedia)ligand lĭgˈənd [key], charged or uncharged molecule with one or more unshared pairs of electrons that can attach to a central metallic atom or ion to form an aggregate known as a complex ion (see c...

Piatra-Neamţ

(Encyclopedia)Piatra-Neamţ pyäˈträ-nyämts [key], city (1990 pop. 118,216), NE Romania, in the Bacău region. Food processing, and the manufacture of fertilizers, furniture, ceramics, and paper are among the in...

rare-earth metals

(Encyclopedia)rare-earth metals, in chemistry, group of metals including those of the lanthanide series and actinide series and usually yttrium, sometimes scandium and thorium, and rarely zirconium. Promethium, whi...

copernicium

(Encyclopedia)copernicium, artificially produced radioactive chemical element; symbol Cn; at. no. 112; mass number of most stable isotope 285; m.p., b.p., sp. gr., and valence unknown. Situated in Group 12 of the p...