Avogadro, Amadeo

1995/08/02 Azkune Mendia, Iñaki - Elhuyar Fundazioa | Kaltzada, Pili - Elhuyar Zientziaren Komunikazioa

• Biografiak

(1776-1856)

Italian physicist born in Turin, Piedmont, on June 9, 1776.

He studied law and in 1800 he began to study mathematics and physics. As he worked in depth the sciences, exercising teaching. In 1809 he was appointed professor of mathematics and physics at the Royal College of Vercelli and from 1820 professor of superior physics at the University of Turin.

The finding of Gay-Lussac indicated that as the temperature increased all gases were distributed in the same proportion and Avogadro studied it, he had an idea. It considers that all gases should have the same number of particles per unit of volume at a given temperature. In 1811 he realized the idea that the particles mentioned did not have what the individual atoms consisted of. There could also be atomic combinations (which we now call molecules).

From there he explained with ease the law of combining volumes of Gay-Lussac. AX. At the beginning of the century Ritter electrolysed water collecting separate oxygen and hydrogen. He was able to verify that the volume of oxygen was half that of hydrogen. Avogadro, applying his hypothesis, showed that the water molecule had two atoms of hydrogen and an oxygen atom. If the total weight of the collected oxygen was eight times higher than that of hydrogen, the oxygen atom was sixteen times heavier (and not, according to Dalton, eight times heavier).

However, Avogadro's ideas were not taken into consideration in the coming decades. Dalton left them and came to Berzelius, the most famous chemist of the time. As a result, the chemicals had large mixtures, inseparable atoms, molecules, atomic weights and molecular weights.

Estanislao Cannizzaro was the first to consider Avogadro, two years after his death, and it was then when he achieved the reputation that tourist science denied him in his life.

Today it is known as Avogadro, because the number bearing its name serves to calculate how many atoms (or molecules) have the atomic weight expressed in grams. Carbon oxide (IV), for example, has a molecular weight 44 and in 44 grams of this gas there will be as many molecules as the number of Avogadro, ie 6,022x1023 molecules (602,600 trilion molecules).

It is also used in chemistry to define mol. Because a mol of substance is the amount that contains 6,022x1023 units of that substance.

Avogadro Quaregna and count of Ceretto during his life and his death took him to Turin on July 9, 1856.