Avogadro constant

The Avogadro constant (symbols: L, N_A) is the number of particles (usually atoms or molecules) in one mole of a given substance.^[2] Its value is equal to 6.02214129(27)×10²³ mol⁻¹.^[3] The constant was named after the Italian scientist Amedeo Avogadro.

Value of NA[1] in various units
6.02214179(30)×1023 mol−1
2.73159757(14)×1026 lb-mol−1
1.707248479(85)×1025 oz-mol−1

The measurement of Avogadro's constant was refined in 2011 to 6.02214078×10²³ ± 0.00000018×10²³.^[4]

An old term closely related to the Avogadro constant is Avogadro's number. Avogadro's number is the number of atoms in 12 grams of the carbon isotope carbon-12. Avogadro's number is a dimensionless quantity and has the numerical value of the Avogadro constant given in base units.

Related pages

• Mole (unit)