Avogadro constant facts for kids
Value of N_{A} in various units 

6.02214179(30)×10^{23} mol^{−1} 
2.73159757(14)×10^{26} lbmol^{−1} 
1.707248479(85)×10^{25} ozmol^{−1} 
The Avogadro constant (symbols: L, N_{A}) is the number of particles (usually atoms or molecules) in one mole of a given substance. Its value is equal to 6.02214129(27)×10^{23} mol^{−1}. The constant was named after the Italian scientist Amedeo Avogadro.
The measurement of Avogadro's constant was refined in 2011 to 6.02214078×10^{23} ± 1.8E7×10^{23}.
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 carbon12. Avogadro's number is a dimensionless quantity and has the numerical value of the Avogadro constant given in base units.
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Images for kids

Ballandstick model of the unit cell of silicon. Xray diffraction measures the cell parameter, a, which is used to calculate a value for Avogadro's constant.