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amino group

(Encyclopedia)amino group, in chemistry, functional group that consists of a nitrogen atom attached by single bonds to hydrogen atoms, alkyl groups, aryl groups, or a combination of these three. An organic compound...

element

(Encyclopedia)CE5 element, in chemistry, a substance that cannot be decomposed into simpler substances by chemical means. A substance such as a compound can be decomposed into its constituent elements by means o...

Barton, Derek H. R.

(Encyclopedia)Barton, Derek H. R., 1918–98, British chemist, b. Gravesend, England, grad. Imperial College of Science and Technology (B.S. 1940, Ph.D. 1942, D.Sc. 1949). He was on the faculty of Imperial College ...

nitrate

(Encyclopedia)nitrate, chemical compound containing the nitrate (NO3) radical. Nitrates are salts or esters of nitric acid, HNO3, formed by replacing the hydrogen with a metal (e.g., sodium or potassium) or a radic...

ammonium group

(Encyclopedia)ammonium group, in chemistry, a positively charged nitrogen atom joined by single bonds to four other atoms or groups. The simplest ammonium group, NH4+, is formed by protonation of ammonia, NH3, e.g....

Fermi, Enrico

(Encyclopedia)Fermi, Enrico ĕnrēˈkō fĕrˈmē [key], 1901–54, American physicist, b. Italy. He studied at Pisa, Göttingen, and Leiden, and taught physics at the universities of Florence and Rome. He contribu...

hydrazine

(Encyclopedia)hydrazine hīˈdrəzēnˌ [key], chemical compound, formula NH2NH2, m.p. 1.4℃, b.p. 113.5℃, specific gravity 1.011 at 15℃. It is very soluble in water and soluble in alcohol. At ordinary tempera...

anaphylaxis

(Encyclopedia)anaphylaxis ănˌəfəlăkˈsĭs [key], hypersensitive state that may develop after introduction of a foreign protein or other antigen into the body tissues. When an anaphylactic state exists, a secon...

nitric oxide

(Encyclopedia)nitric oxide or nitrogen monoxide, a colorless gas formed by the combustion of nitrogen and oxygen as given by the reaction: energy + N2 + O2 → 2NO; m.p. −163.6℃; b.p. −151.8℃. Nitric oxide ...

combustion

(Encyclopedia)combustion, rapid chemical reaction of two or more substances with a characteristic liberation of heat and light; it is commonly called burning. The burning of a fuel (e.g., wood, coal, oil, or natura...