Columbia Encyclopedia

Search results

438 results found

sodium nitrate

(Encyclopedia)sodium nitrate, chemical compound, NaNO3, a colorless, odorless crystalline compound that closely resembles potassium nitrate (saltpeter or niter) in appearance and chemical properties. It is soluble ...

electron

(Encyclopedia)electron, elementary particle carrying a unit charge of negative electricity. Ordinary electric current is the flow of electrons through a wire conductor (see electricity). The electron is one of the ...

states of matter

(Encyclopedia)states of matter, forms of matter differing in several properties because of differences in the motions and forces of the molecules (or atoms, ions, or elementary particles) of which they are composed...

Leggett, Sir Anthony James

(Encyclopedia)Leggett, Sir Anthony James, 1938–, British physicist, Ph.D. Oxford, 1964. He was a professor at Sussex Univ., England, from 1967 to 1983, when he joined the faculty at the Univ. of Illinois at Urban...

Moissan, Henri Ferdinand Frederick

(Encyclopedia)Moissan, Henri Ferdinand Frederick, 1852–1907, French chemist, Ph.D. École Pratique des Haute Études, Paris, 1880. Moissan was a professor at the School of Pharmacy in Paris (1886–1900) and at t...

castor oil

(Encyclopedia)castor oil, yellowish oil obtained from the seed of the castor bean. The oil content of the seeds varies from about 20% to 50%. After the hulls are removed the seeds are cold-pressed. Medicinal castor...

Biot, Jean Baptiste

(Encyclopedia)Biot, Jean Baptiste zhäN bätēstˈ byō [key], 1774–1862, French physicist, grad. École Polytechnique (1797). He taught mathematics at Beauvais before becoming (1800) professor of mathematical ph...

water glass

(Encyclopedia)water glass or soluble glass, colorless, transparent, glasslike substance available commercially as a powder or as a transparent, viscous solution in water. Chemically it is sodium silicate, potassium...

germanium

(Encyclopedia)germanium jərmāˈnēəm [key] [from Germany], semimetallic chemical element; symbol Ge; at. no. 32; at. wt. 72.63; m.p. 937.4℃; b.p. 2,830℃; sp. gr. 5.323 at 25℃; valence +2 or +4. Pure german...

isomer

(Encyclopedia)isomer īˈsəmər [key], in chemistry, one of two or more compounds having the same molecular formula but different structures (arrangements of atoms in the molecule). Isomerism is the occurrence of ...