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cyclic compound

(Encyclopedia)cyclic compound, any one of a class of compounds whose molecules contain a number of atoms bonded together to form a closed chain or ring. If all of the atoms that form the ring are carbon, the compou...

Ponca City

(Encyclopedia)Ponca City, city (1990 pop. 26,359), Kay co., N Okla., on the Arkansas River; founded 1893 with the opening of the Cherokee Strip, inc. 1899. It is a trade, processing, and shipping hub in a grain, li...

microphone

(Encyclopedia)microphone, device for converting sound into electrical energy, used in radio broadcasting, recording, and sound amplifying systems. Its basic component is a diaphragm that responds to the pressure or...

hydrate

(Encyclopedia)hydrate hīˈdrāt [key], chemical compound that contains water. A common hydrate is the familiar blue vitriol, a crystalline form of cupric sulfate. Chemically, it is cupric sulfate pentahydrate, CuS...

inorganic chemistry

(Encyclopedia)inorganic chemistry, the study of all the elements and their compounds with the exception of carbon and its compounds, which fall under the category of organic chemistry. Inorganic chemistry investiga...

low-temperature physics

(Encyclopedia)low-temperature physics, science concerned with the production and maintenance of temperatures much below normal, down to almost absolute zero, and with various phenomena that occur only at such tempe...

ecology

(Encyclopedia)ecology, study of the relationships of organisms to their physical environment and to one another. The study of an individual organism or a single species is termed autecology; the study of groups of ...

Le Bel, Joseph Achille

(Encyclopedia)Le Bel, Joseph Achille zhôsĕfˈ äshēlˈ ləbĕl [key], 1847–1930, French chemist. He was educated at the École polytechnique and carried out much of his research in his own private laboratory. ...

Kekulé von Stradonitz, Friedrich August

(Encyclopedia)Kekulé von Stradonitz, Friedrich August frēˈdrĭkh ouˈgo͝ost kāˈko͞olā fən shträˈdōnĭts [key], 1829–96, German organic chemist. He was professor at Ghent (1858–65) and at Bonn from 1...

Hemet

(Encyclopedia)Hemet hĕmˈĭt [key], city (2020 pop. 89,833), Riverside co., S Calif., in the San Jacinto v...