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law of simple multiple proportions

(Encyclopedia)law of simple multiple proportions, in chemistry, the statement that when two or more elements form more than one compound, the ratio of the weights of one element that combine with a given weight of ...

lake, in dyeing

(Encyclopedia)lake, in dyeing, an insoluble pigment formed by the reaction between an organic dye and a mordant. The color of a lake depends upon the mordant as well as the dye used. Generally, lakes are not as col...

ozone

(Encyclopedia)ozone ōˈzōn [key], an allotropic form of the chemical element oxygen (see allotropy). Pure ozone is an unstable, faintly bluish gas with a characteristic fresh, penetrating odor. The gas has a dens...

chemistry

(Encyclopedia)chemistry, branch of science concerned with the properties, composition, and structure of substances and the changes they undergo when they combine or react under specified conditions. Organic chemi...

carbon dioxide

(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...

Berthelot, Pierre Eugène Marcelin

(Encyclopedia)Berthelot, Pierre Eugène Marcelin pyĕr ûzhĕnˈ märsəlăNˈ bĕrtəlōˈ [key], 1827–1907, French chemist. He was professor at the École Supérieure de Pharmacie (1859) and at the Collège de ...

tyrosine

(Encyclopedia)CE5 tyrosine tīˈrəsēn [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer appears in mammalian protein. It is not essential to the huma...

Wollaston, William Hyde

(Encyclopedia)Wollaston, William Hyde, 1766–1828, English scientist, M.D. Cambridge, 1793. His wide-ranging scientific achievements include the discovery (1802) of the dark lines (Fraunhofer lines) in the solar s...

fog

(Encyclopedia)fog, aggregation of water droplets or ice crystals immediately above the surface of the earth (i.e., a cloud near the ground). A light or thin fog is usually called a mist. Fog may occur when the mois...

carbonyl group

(Encyclopedia)carbonyl group kärˈbənĭl [key], in chemistry, functional group that consists of an oxygen atom joined by a double bond to a carbon atom. The carbon atom is joined to the remainder of the molecule ...