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Gram's stain

(Encyclopedia)Gram's stain, laboratory staining technique that distinguishes between two groups of bacteria by the identification of differences in the structure of their cell walls. The Gram stain, named after its...

Avogadro, Amedeo, conte di Quaregna

(Encyclopedia)Avogadro, Amedeo, conte di Quaregna ämādāˈō kônˈtā dē kwärāˈnyä ävōgäˈdrō [key], 1776–1856, Italian physicist, b. Turin. He became professor of physics at the Univ. of Turin in 182...

molecular biology

(Encyclopedia)molecular biology, scientific study of the molecular basis of life processes, including cellular respiration, excretion, and reproduction. The term molecular biology was coined in 1938 by Warren Weave...

molecular formula

(Encyclopedia)molecular formula: see formula. ...

molecular modeling

(Encyclopedia)molecular modeling, the computer simulation, by various means, of chemical structures or processes. Special computer-graphics programs can display three-dimensional images of molecular structures and ...

kinetic-molecular theory of gases

(Encyclopedia)kinetic-molecular theory of gases, physical theory that explains the behavior of gases on the basis of the following assumptions: (1) Any gas is composed of a very large number of very tiny particles ...

molecular orbital theory

(Encyclopedia)molecular orbital theory, detailed explanation of how electrons are distributed in stable molecules. In the simpler valence theory of the chemical bond, each atom in a molecule is assumed to retain it...

number-average molecular weight

(Encyclopedia)number-average molecular weight: see molecular weight. ...

weight-average molecular weight

(Encyclopedia)weight-average molecular weight: see molecular weight. ...

heat

(Encyclopedia)heat, nonmechanical energy in transit, associated with differences in temperature between a system and its surroundings or between parts of the same system. The study of heat and its relationship ...