Lorenzo Romano Amedeo Carlo Avogadro, the Count of Quaregna and Cerreto, born in Turin, Italy, on August 9, 1776, was an Italian lawyer, chemist and physicist who distinguished atom from molecule.

His father Count Fellipo Avogadro was an important lawyer and was elected president of the Piedmont Senate in 1779.

In Turin, he pursued his career as an ecclesiastical lawyer and became a bachelor in 1792 at the age of 16. After 4 years completed his doctorate in the legal area. He was secretary of the city hall of Eridano. But his interest in science was great and he began to study physics and chemistry on his own.

In the year 1809, he began to teach physics at the Realle Collegio de Varcelli. At the University of Turin in 1820, he joined as chair of the chair of physics. He published several works for 30 years, the period he was there.

The best known work of Avogadro is the Avogadro Number which is a constant that was determined in 1865. The Avogadro Number is 6.02252.1023 and indicates the number of molecules that exist in one mole of any substance. It is an extremely large number.

Avogadro Volume is the volume occupied by 1 mol of any gas under normal temperature and pressure (273 K and 1 atm), the CNTP. This value was calculated by the Austrian physicist Joseph Loschmidt (1821 - 1895), and is worth 22,412 liters.

Avogadro also established the Avogadro Hypothesis, where he states that "equal volumes of different gases at the same temperature and pressure contain the same number of molecules."

It also established the chemical formula of water, H2O instead of HO, as was previously known. He was married to Felicitá Mazzé and had 6 children. His ideas were not widely accepted by the scientific community of the time.
Avogadro died on July 9, 1856, in Turin.