Columbia Encyclopedia

(Encyclopedia) concentration, in chemistry, measure of the relative proportions of two or more quantities in a mixture. The concentration of a solute is very important in studying chemical reactions because it deter...

(Encyclopedia) charcoal, substance obtained by partial burning or carbonization (destructive distillation) of organic material. It is largely pure carbon. The entry of air during the carbonization process is control...

(Encyclopedia) hydrocarbon hīˌdrōkärˈbən [key], any organic compound composed solely of the elements hydrogen and carbon. The hydrocarbons differ both in the total number of carbon and hydrogen atoms in their ...

(Encyclopedia)  CE5 Greater celandine poppy, Chelidonium majus poppy, common name for some members of the Papaveraceae, a family composed chiefly of herbs of the Northern Hemisphere having a characteristic milky ...

(Encyclopedia) pepper, name for the fruits of several unrelated Old and New World plants used as spices or vegetables or in medicine. True pepper is classified in the division Magnoliophyta, class Magnoliopsida,...

(Encyclopedia) fluorine flo͞oˈərēn, –rĭn [key], gaseous chemical element; symbol F; at. no. 9; at. wt. 18.9984; m.p. −219.6℃; b.p. −188.14℃; density 1.696 grams per liter at STP; valence −1. Fluorin...

(Encyclopedia) tapeworm, name for the parasitic flatworms forming the class Cestoda. All tapeworms spend the adult phase of their lives as parasites in the gut of a vertebrate animal (called the primary host). Most ...

(Encyclopedia) Grass, Günter günˈtər gräs [key], 1927–2015, German novelist, lyricist, artist, and playwright, b. Danzig (now Gdańsk, Poland). Writing from his experience in the Hitler Youth, the German army...

(Encyclopedia) carbon dioxide, chemical compound, CO2, a colorless, odorless, tasteless gas that is about one and one-half times as dense as air under ordinary conditions of temperature and pressure. It does not bur...

(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...