He August 9, 1776 , in the Italian city of Turin , the birth of Amedeo Avogadro . This deceased chemist and physicist at 79 years old was in history for his contributions to the field of sciences : in fact, today we know by name a law or principle and a number or constant.
It must be established that Amadeo gave an important boost to the study of atomic theory and that he developed his famous law based on other theories such as those created by Gay-Lussac and John Dalton.
It is interesting to know that, at first, when he made known his works and his aforementioned law, he did not have the support or interest of most of the scientific community. He was simply ignored and that, shortly after, other scientists came to endorse his discoveries with others of his own that they had carried out on their own.
We had to wait a long time for his work to be recognized. Specifically, that happened when works such as those of Williamson, Gerhardt or Laurent were presented that made it clear that Amedeo was right. And not only that but they also showed that his statements and his work were absolutely indispensable in the field of physics.
The Avogadro's law refers to the characteristics of the ideal gases (theoretical). Avogadro warned that the relative densities of gas , when the same temperature and pressure conditions are recorded, they are proportional to their atomic weights. From this, he formulated his hypothesis: according to Avogadro , gases with the same volume, when measured under identical conditions of temperature and pressure, have the same amount of particles (atoms or molecules).
By extension, the Avogadro's law indicates that the quantity of molecules of two different gases occupy an identical volume when they are in the same conditions of temperature and Pressure .
Continuing with his reasoning, Avogadro postulated that a mol (unit of measurement) of different substances contains the same amount of molecules. This number has a value known as Avogadro's number : 6.022045 x 10 raised to 23 .
He Avogadro's number , therefore, reveals the amount of elementary entities (molecules , atoms, ions, electrons) found in one mole of any substance. On the mole, we must take into account that it is equivalent to the number of atoms present in twelve grams of pure carbon-12 .
Numerous are the illustrious characters who, throughout history, have not hesitated to highlight, in an overwhelming way, the important role developed by Avogadro as well as its constant. Specifically, the most relevant include the following:
-The French physicist Jean Perrin, winner of the Nobel Prize in 1926, who owed part of his work to the advances mentioned by the aforementioned Amedeo Avogadro.
-The Austrian chemist and physicist Johann Josef Loschmidt, who is considered one of the first students of molecular size and atomic valence.