The number of items in a mole, approximately 6.0221 × 1023 .
The number of atoms or molecules in a mole of a substance, approximately 6.0225 × 1023 . It is based on the number of carbon atoms in 12 grams of carbon 12.
Origin of avogadro-s-number
Named after Amadeo Avogadro (1776 - 1856)