Avogadro was active in the revolutionary movement of March 1821. Turin was now the capital of the restored Savoyard Kingdom of Sardinia under Victor Emmanuel I. In 1820, he became a professor of physics at the University of Turin. Avogadro submitted this essay to Jean-Claude Delamétherie's Journal de Physique, de Chimie et d'Histoire naturelle ('Journal of Physics, Chemistry and Natural History'). In 1811, he published an article with the title Essai d'une manière de déterminer les masses relatives des molécules élémentaires des corps, et les proportions selon lesquelles elles entrent dans ces combinaisons ('Essay on a manner of Determining the Relative Masses of the Elementary Molecules of Bodies and the Proportions by Which They Enter These Combinations'), which contains Avogadro's hypothesis. Soon after, he dedicated himself to physics and mathematics (then called positive philosophy), and in 1809 started teaching them at a liceo (high school) in Vercelli, where his family lived and had some property. He graduated in ecclesiastical law at the late age of 20 and began to practice. This constant is denoted N A, and is one of the seven defining constants of the SI.īiography Essay on the mathematical theory of the distribution of electricity on the surface of conducting bodies, 1844Īmedeo Avogadro was born in Turin to a noble family of the Kingdom of Sardinia (now part of Italy) in the year 1776. In tribute to him, the ratio of the number of elementary entities ( atoms, molecules, ions or other particles) in a substance to its amount of substance (the latter having the unit mole), 6.022 140 76 ×10 23 mol −1, is known as the Avogadro constant. Lorenzo Romano Amedeo Carlo Avogadro, Count of Quaregna and Cerreto ( / ˌ æ v ə ˈ ɡ ɑː d r oʊ/, also US: / ˌ ɑː v-/, Italian: 9 August 1776 – 9 July 1856) was an Italian scientist, most noted for his contribution to molecular theory now known as Avogadro's law, which states that equal volumes of gases under the same conditions of temperature and pressure will contain equal numbers of molecules.

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