Avogadro

Avogadro's number (6.022 x 10^23) defines the count of constituent particles in one mole of substance.

Named after Amedeo Avogadro, this fundamental constant bridges atomic and macroscopic scales. One mole of carbon-12 atoms weighs exactly 12 grams, and each of those atoms contributes to the ensemble measured by this number.

The constant enables chemistry to translate between individual molecular events and laboratory-scale quantities. Stoichiometric calculations, gas laws, and thermodynamics all rely on Avogadro's number as a unit-conversion anchor.

In 2019, the SI redefinition fixed the value at exactly 6.02214076 x 10^23 mol^-1, removing its dependence on the kilogram prototype.

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