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Named after Italian physicist Amedeo Avogadro (1776–1856).
Etymology from Wiktionary, CC BY-SA 4.0.
Avogadro's number
Today it means: The number of elementary entities (atoms or molecules) comprising one mole of a given substance, being precisely 6.02214076 × 10²³. Formerly defined as the number of atoms present in 12 grams of isotopically pure carbon-12. Full definition →