Columbia Encyclopedia

Search results

500 results found

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...

mixture

(Encyclopedia)mixture, in chemistry, a physical combination of two or more pure substances (i.e., elements or compounds). A mixture is distinguished from a compound, which is formed by the chemical combination of t...

Charlotte, city, United States

(Encyclopedia)Charlotte, city (2020 pop. 874,579), seat of Mecklenburg co., S N.C.; inc. 1768. The largest city in the state and the commercial and industrial leader ...

cutlery

(Encyclopedia)cutlery, various types of implements for cutting, preparing, and eating food. In addition to different kinds of knives and the steels to sharpen them, the term usually encompasses forks and spoons. Th...

transmutation of elements

(Encyclopedia)transmutation of elements, conversion of one chemical element into another. The expression has both historical and contemporary significance. The transmutation of certain metals into gold by means of ...

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...

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....

stealth technology

(Encyclopedia)stealth technology, designs and materials engineered for the military purpose of avoiding detection by radar or any other electronic system. Stealth, or antidetection, technology is applied to vehicle...

table

(Encyclopedia)table, article of furniture employed for household or ecclesiastical purposes. Elaborately decorated tables of wood or metal were known in ancient Egypt and Assyria, and the Greeks used small tables o...