Amedeo Avogadro: biography and contributions of this Italian physicist and chemist

Amedeo Avogadro is known by the formula that developed and to which he gave his name, the law of Avogadro, based on the fact that when different substances in the gaseous state, being in identical measurements of temperature and pressure, also contain the same numerical amount of molecules.

In addition to carrying out extensive teaching and research work, Avogadro was linked to politics in his country, which led to the loss of his chair at the University of Turin, where he worked for several years.

here we will review the life of this researcher through a biography of Amedeo Avogadro, and his major contributions to science will also be discussed.

    Brief biography of Amedeo Avogadro

    Lorenzo Romano Amedeo Carlo Avogadro, Count of Quaregna i Cerreto, better known as Amedeo Avogadro, was born in Turin on August 9, 1776. He was the son of a magistrate named Filippo Avogadro.

    Academic training

    In 1796, Amedeo Avogadro graduated in canon law, following in his father’s footsteps, and later enrolled as a lawyer in the city of Turin.

    However, his work did not excite him, while mathematics and physics, subjects in which he engaged alone. For this reason, he decided to begin his studies in physics and mathematics in 1800.

    In 1809, at the age of 33, he obtained a post as professor of physics at the Royal College, a high school in Vercelli, a town in northern Italy.

    During his stay in Vercelli, he combined teaching with the work of a researcher, finding that when two volumes of hydrogen gas were combined with one volume of oxygen gas, two volumes of water vapor were produced.

      Stage of great development as a scientist: discovery of Avogadro’s law

      As Amedeo Avogadro continued his work as a professor of physics at the Royal College, he did not stop researching and in 1811, he developed a hypothesis which several years later became famous within the scientific community, called Avogadro’s law, which will be explained in more detail later.

      He later sent the dissertation on his theory of Avogadro’s law to the Journal of Physics, entitled “Essay on a way of determining the relative masses of elementary molecules of bodies, and the proportions in which they enter into these combinations”.

      It should be noted that this test did not reach its deserved importance until 50 years later, in particular thanks to the work of the Italian chemist Cannizzaro, who presented Avogadro’s theory at a congress of chemists in 1860 in Karlsruhe (Germany). ), being the reformist principle of Cannizzaro, a fact which supposed the implantation of a concept and also of a reliable method to be able to determine the atomic weights, as well as the corresponding formulas of composition of the substances.

      At that time, by exposing the theory he had developed he had to overcome several difficulties, one of which was the great confusion that existed to differentiate atoms and molecules, it has therefore greatly contributed to clarifying the differences between these two concepts.

      While it is true that he did not use the word atom in his research, as the words atom and molecule were considered synonymous, Avogadro differentiated three classes of molecules, one of which is called the elementary molecule. an atom, thus leaving a first step in the clarification between atoms and molecules.

      In 1814 Avogadro published his “Report on the relative masses of molecules of simple bodies, or expected densities of their gases, and on the constitution of some of their compounds, to serve later as a test on the same subject.”, Of which research focused on the density of gases.

      As for his personal life, in 1815, Avogadro married Felicita Mazzé; together they had six children.

        First step as a professor of physics at the University of Turin

        After teaching physics at the Royal College of Vercelli for 11 years in 1820, Avogadro stopped teaching at this secondary school. get a job as a professor of physics at the famous University of Turin, where he will soon become the first professor of mathematical physics (known at the time as sublime physics).

        The year following his debut at the University of Turin (1821), Avogadro published a report entitled “New Considerations on the Theory of Determined Proportions in Combinations and on the Determination of the Masses of Body Molecules”. How to include organic compounds in the ordinary laws of certain proportions. “

        Outside the academic context, Avogadro was part of the political revolution movements that opposed the King of Sardinia, causing him to lose his chair at the university in 1823., retaining only a modest pension and the title of professor emeritus.

          Return to the University of Turin and completion of its scientific work

          In 1833 Avogadro managed to regain his old post at the University of Turin, thanks to his great work as a researcher, for which his work was beginning to stand out.

          It was in 1941 that Amedeo Avogadro published his scientific works grouped into 4 four volumes entitled “Physique des corps ponderabili, or Treatise on the material constitution of ‘bodies” (Physics of ponderable bodies or treatise on the material constitution of bodies), serving this research for the development of laws, hypotheses and theories of post-Avogadro authors.

          In 1850 he ended his career as a professor at the University of Turin and, six years later, he died in his hometown of Turin at the age of 79.

            Discoveries of Amedeo Avogadro

            These are the main scientific contributions by Amedeo Avogadro.

            Avogadro’s Law

            To develop his theory, Avogadro followed John Dalton’s atomic theory of motion vectors in a molecule.

            Dalton’s research is to establish the importance of atomic weights, that is to say the relative weight of the particles that make up the bodies. This is why Dalton’s theory for calculating atomic weights was a breakthrough for science and allowed other scientists to progress based on their discovery.

            Through calculating the weight of atoms, John Dalton was also able to develop the Law of Multiple Proportions, which was supported by French physicist and chemist Louis Joseph Gay-Lussac, it is based on the fact that when two or more elements are combined to create different compounds, once the stationary mass of one of the compounds is given, the mass of the other compound is combined with this stationary mass, and the second is linked to canonical and indistinct numbers.

            Based on Dalton’s theory, Avogadro developed a way to simply calculate the mass of molecules of bodies that have the possibility of changing to a gaseous state and the numerical quantity of these molecules.

            His hypothesis said that when different gases have the same volume and are under similar temperature and pressure conditions, the number of molecules they contain is the same.

            Avogadro’s number

            The Avogadro number, currently called the Avogadro constant, is used in chemistry to denote the number of particles that make up a substance, usually molecules or atoms, that can be found in the amount of one mole of that substance.

            It is a factor of proportion which makes it possible to relate the molar mass of a substance (it is the physical quantity which makes it possible to define the mass of this substance by the unit of quantity of substance, expressed in kg / mol ) and the excess that is present in a sample.

            Bibliographical references

            • Avogadro, A. (1811). Test a way to determine the relative masses of elementary molecules in bodies and the proportions in which they enter these compounds. Journal of Physics, 73, p. 58-76.
            • Morselli, M. (1984). Amedeo Avogadro: a scientific biography. Netherlands: D. Reidel Publishing Company.
            • Moore, FJ (1918). A history of chemistry. New York: McGraw-Hill Book Company.
            • Muñoz, R. and Bartomeu, JR (2003). The history of science in textbooks: Avogadro’s hypothesis (s). Science education, 21 (1), p. 147-159.

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