avogadro's number chemistry
Avogadro's Number Definition. Avogadro's number or Avogadro's constant is the number of particles found in one mole of a substance. It is the number of atoms in exactly 12 grams of carbon-12. This experimentally determined value is approximately 6.0221 x 10 23 particles per mole. Note, Avogadro's number, on its own, is a dimensionless quantity. Avogadro's number may be designated using the symbol L or N A.