adad-e Avogâdro (#)
Fr.: Nombre d'Avogadro
The number of atoms in 12 grams of 12C; by extension, the number of atoms in a gram-atom (or the number of molecules in a → mole) of any substance: 6.02 × 1023.
Named after Amedeo Avogadro (1776-1856), whose law allowed other physicists to calculate Avogadro's number; → number.