Avogadro's Number

number indicating the quantity of atoms in a gram atom or molecules in a gram molecule (Chemistry)

The Avogadro constant (symbols: L, NA), also called the Avogadro number is the number of "entities" (usually, atoms or molecules) in one mole, that is the number of carbon-12 atoms in 12 grams (0.012 kg) of unbound carbon-12 in its ground state. The current best estimate of this number is: The value of the number was first indicated by Johann Josef Loschmidt, who in 1865, computed the number of particles in one cubic centimetre of gas in standard conditions. The term Loschmidt constant is thus more correctly applied for this latter value, which can be said to be proportional to the Avogadro number. However, in German language literature, "Loschmidt constant" is used to refer to both this usage, as well as the number of entities in a mole.
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Noun
1. the number of molecules in a mole of a substance (approximately 602,250,000,000,000,000,000,000)
(synonym) Avogadro's number
(hypernym) constant

Noun
1. the number of molecules in a mole of a substance (approximately 602,250,000,000,000,000,000,000)
(synonym) Avogadro number
(hypernym) constant

 Say it 
(NA, L) The number of particles in one mole, equal to 6.02214199 × 1023 mol-1 (± 0.00000047 mol-1) [1998 CODATA values ]

NUMERO DI AVOGADRO