Avogadro's number

noun

, Chemistry.

1. the constant, 6.022 × 10 23 , representing the number of atoms, molecules, or ions in one mole of a substance. : N Compare gram-atom, gram molecule.

Avogadro's number

1. The number of atoms or molecules in a mole of a substance, approximately 6.0225 × 10 ²³. It is based on the number of carbon atoms in 12 grams of carbon 12.

Word History and Origins

Origin of Avogadro's number¹

First recorded in 1925–30; Avogadro's law