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

Amedeo Avogadro is known for the formula he developed and named after him, Avogadro's law., based on the fact that when different substances in the gaseous state, when found in identical measurements of temperature and pressure, also contain the same numerical quantity of molecules.

In addition to carrying out extensive teaching and research work, Avogadro was linked to politics in his country, which resulted in 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 the main contributions of him to science will also be discussed.

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Brief biography of Amedeo Avogadro

Lorenzo Romano Amedeo Carlo Avogadro, the Count of Quaregna y 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 the footsteps of his father, and later registered as a lawyer in the city of Turin.

Nevertheless, He was not passionate about his work, while mathematics and physics did., subjects he devoted himself to on his own account. For this reason, he decided to begin his studies in physics and mathematics in the year 1800.

In 1809, at the age of 33, he got a position as a physics teacher at the Royal College, a secondary school located in Vercelli, a city in northern Italy.

While at Vercelli he combined teaching with research work, coming to discover that when two volumes of hydrogen gas were combined with one volume of oxygen gas, two volumes of water vapor were produced.

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

While Amedeo Avogadro continued his work as professor of physics at the Royal College, he did not stop investigating and In 1811 he elaborated a hypothesis that several years later became famous within the scientific community, named as Avogadro's law., which will be explained in more detail later.

Subsequently, he sent the memoir on his theory of Avogadro's law to the Journal de Physique, entitled “Essay on a form of determine the relative masses of the elemental molecules of the bodies, and the proportions according to which they enter these combinations ”.

It should be noted that this essay did not have the importance it deserved until 50 years later, especially thanks to the work of the Italian chemist Cannizzaro, who made known Avogadro's theory in a Congress of chemists in 1860 in Karlsruhe (Germany), being the reformist principle of Cannizzaro, which supposed the implementation of a concept and also of a reliable method to be able to determine the atomic weights, as well as the corresponding formulas for the composition of the substances.

At that time, by exposing the theory that he had developed he had to overcome various difficulties, one of them being the great confusion that existed to differentiate atoms and moleculesSo he made a great contribution in clarifying the differences between these two concepts.

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

In 1814, Avogadro published his “Memoir on the relative masses of the molecules of simple bodies, or expected densities of their gas, and on the constitution of some of his compounds, to then serve as a test on the same subject ”, whose research dealt with the density of the gases.

In regards to his personal life, In 1815, Avogadro married Felicita Mazzé; together they had six children.

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First stage as professor of physics at the University of Turin

After serving as a physics teacher at the Royal College of Vercelli for 11 years, in 1820, Avogadro stopped teaching at this secondary education center, getting a position as professor of physics at the renowned University of Turin, a place where he shortly after he would become the first professor of mathematical physics (known in those days as sublime physics).

The year after starting at the University of Turin (1821), Avogadro published a memoir called “New considerations on the theory of the proportions determined in the combinations, and on the determination of the masses of the molecules of the bodies "and shortly afterwards he published “Memory on how to include organic compounds in the ordinary laws of proportions determined ”.

Outside of 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.

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Restitution at the University of Turin and culmination of his scientific works

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

It is in 1941 when Amedeo Avogadro publishes his scientific works grouped in 4 four volumes entitled “Fisica dei corpi ponderabili, ossia Trattato della costituzione materiale di 'corpi ”(Physics of ponderable bodies or treatise on the constitution material of the bodies), serving these investigations for the development of laws, hypotheses and theories of authors after Avogadro.

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

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Discoveries of Amedeo Avogadro

These are the main scientific contributions scored by Amedeo Avogadro.

Avogadro's Law

To elaborate his theory, Avogadro followed the atomic theory of John dalton about the vectors of motion in a molecule.

Dalton's investigations consist in fixing the importance of atomic weights, that is, the relative weight of the particles that make up the bodies. That is why Dalton's theory to calculate atomic weights was a great advance for science and allowed other scientists to advance based on his discovery.

Through the calculation of the weight of atoms, John Dalton was also able to develop the law of multiple proportions, which was supported by the physicist and French chemist Louis Joseph Gay-Lussac, is based on the fact that when two or more elements are combined to create different compounds, once the mass is given immovable of one of the compounds, the mass of the other compound is combined with said immovable mass, and the second has as relation canonical numbers and indistinct.

Based on Dalton's theory, Avogadro he developed a way to calculate in a simple way the mass of the molecules of bodies that have the possibility of passing into a gaseous state and the numerical number of those molecules.

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

Avogadro's number

Avogadro's number, currently referred to as Avogadro's constant, is used in chemistry to designate the number of particles that make up a substance, commonly being molecules or atoms, which can be found in the amount of one mole of said substance.

It is a proportion factor that allows relating the molar mass of a substance (it is the physical magnitude that allows defining the mass of said substance per unit quantity of substance, expressed in kg / mol) and the mass that is present in a shows.