Columbia Encyclopedia

Search results

440 results found

lancelet

(Encyclopedia)lancelet, name for small, fishlike lower chordate (see Chordata), also called amphioxus; it shows many affinities with the vertebrates. There are about 30 lancelet species, most belonging to the genus...

chocolate

(Encyclopedia)chocolate, general term for the products of the seeds of the cacao or chocolate tree, used for making beverages or confectionery. The flavor of chocolate depends not only on the quality of the cocoa n...

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 ...

electrodynamics

(Encyclopedia)electrodynamics, study of phenomena associated with charged bodies in motion and varying electric and magnetic fields (see charge; electricity); since a moving charge produces a magnetic field, electr...

cloud

(Encyclopedia)CE5 Approximate heights of some types of clouds cloud, aggregation of minute particles of water or ice suspended in the air. Cloudiness (or proportion of the sky covered by any form of cloud),...

ameba

(Encyclopedia)ameba or amoeba both: əmēˈbə [key], common name for certain one-celled organisms belonging to the phylum Sarcodina of the kingdom Protista. Amebas were previously classified as members of the anim...

reading, mental process

(Encyclopedia)reading, process of mentally interpreting written symbols. Facility in reading is an essential factor in educational progress, and instruction in this basic skill is a primary purpose of elementary ed...

Euclid, Greek mathematician

(Encyclopedia)Euclid yo͞oˈklĭd [key], fl. 300 b.c., Greek mathematician. Little is known of his life other than the fact that he taught at Alexandria, being associated with the school that grew up there in the l...

virus

(Encyclopedia)CE5 Structure of a tobacco mosaic virus, an RNA-containing virus virus, parasite with a noncellular structure composed mainly of nucleic acid within a protein coat. Most viruses are too small (100...

algebra

(Encyclopedia)algebra, branch of mathematics concerned with operations on sets of numbers or other elements that are often represented by symbols. Algebra is a generalization of arithmetic and gains much of its pow...