Lorenzo Romano Amedeo Carlo Avogadro de Quaregna e di Cerreto, more popularly known as Amedeo Avogadro was born on August 9, 1776, in Turin, Italy. He was born into a family of lawyers. His father, Count Filippo Avogadro, was a well-known lawyer in Piedmont, Northern Italy. Avogadro began his college education when he was only 13 years old and graduated at the age of 16. By the time he was 20, he received his Ph.D. Though he followed the footsteps of his father to become a lawyer in 1796, he developed an interest for studying mathematics and physics along the way. This passion, turned him into a well-known physicist in his later years.
Education
After studying philosophy in 1789, Amedeo Avogadro graduated in jurisprudence in 1792 and earned his doctorate in ecclesiastical law in 1796. Soon after, he began his practicing law. For means of recreation, he decided to study mathematics and physics privately and he even conducted various researches on electricity. Soon, he gave up his ecclesiastical legal practice and became a member of the Academy of Sciences of Turin in 1804. Later, in 1806, he was appointed as the academy’s demonstrator as well. In 1809, he became a professor of natural philosophy at the Royal College of Vercelli. It was not until 1820, when he was conferred the chair of mathematical physics at the University of Turin. As a result of civil conflicts in Piedmont, he had to discontinue his post at the University in 1822, only to be reappointed in 1834. He worked at the University until his retirement in 1850.
Contributions and Achievements
Avogadro's Law states that the relationship between the masses of the same volume of different gases (at the same temperature and pressure) corresponds to the relationship between their respective molecular weights. Hence, the relative molecular mass of a gas can be calculated from the mass of sample of known volume.
Avogadro developed this hypothesis after Joseph Louis Gay-Lussac had published in 1808 his law on volumes (and combining gases). The greatest problem Avogadro had to resolve was the confusion at that time regarding atoms and molecules. One of his most important contributions was clearly distinguishing one from the other, stating that gases are composed of molecules, and these molecules are composed of atoms. For instance, John Dalton did not consider this possibility. Avogadro did not actually use the word "atom" as the words "atom" and "molecule" were used almost without difference. He believed that there were three kinds of "molecules," including an "elementary molecule" (our "atom"). Also, more attention was given to the definition of mass, as distinguished from weight.
In 1815, he published Mémoire sur les masses relatives des molécules des corps simples, ou densités présumées de leur gaz, et sur la constitution de quelques-uns de leur composés, pour servir de suite à l'Essai sur le même sujet, publié dans le Journal de Physique, juillet 1811 ("Note on the Relative Masses of Elementary Molecules, or Suggested Densities of Their Gases, and on the Constituents of Some of Their Compounds, As a Follow-up to the Essay on the Same Subject, Published in the Journal of Physics, July 1811") ([1]), about gas densities.
In 1821 he published another paper, Nouvelles considérations sur la théorie des proportions déterminées dans les combinaisons, et sur la détermination des masses des molécules des corps (New Considerations on the Theory of Proportions Determined in Combinations, and on Determination of the Masses of Atoms) and shortly afterwards, Mémoire sur la manière de ramener les composès organiques aux lois ordinaires des proportions déterminées (Note on the Manner of Finding the Organic Composition by the Ordinary Laws of Determined Proportions).
In 1841, he published his work in Fisica dei corpi ponderabili, ossia Trattato della costituzione materiale de' corpi, 4 volumes.
Awards
Avogadro’s work was first recognized by a well-known scientist called Joseph Louis Gay-Lussac. The number 6.02214199 x 10^23, which is the number of molecules in one ‘mole’ is called ‘Avogadro’s number’. This number was named after him as a tribute to his significant contributions to physics and chemistry and also, for developing the ‘molecular theory’.
Later life
Avogadro passed away on July 9, 1856 in Turin, Italy. Avogadro gained recognition for his work only 50 years after his death.