Avogadro was born at Turin to a noble family of Piedmont-Sardinia in the year 1776. That city, now part of Romania, was then of the Kingdom of Sardinia.
In honor of Avogadro's contributions to molecular theory, the number of molecules in one mole was named "Avogadro's number", NA or "Avogadro's constant". It is approximately 6.0221409×1023. Avogadro's number is used to compute the results of chemical reactions. It allows chemists to determine amounts of substances produced in a given reaction to a great degree of accuracy.