Avogadro's number (redirected from Avogadro constant)

Avogadro's number (ävōgä`drō) [for Amedeo Avogadro], number of particles contained in one mole of any substance; it is equal to 602,252,000,000,000,000,000,000, or in scientific notation, 6.02252×10²³. For example, 12.011 grams of carbon (one mole of carbon) contains 6.02252×10²³ carbon atoms, and 180.16 grams of glucose, C₆H₁₂O₆, contains 6.02252×10²³ molecules of glucose. Avogadro's number is determined by calculating the spacing of the atoms in a crystalline solid through X-ray methods and combining this data with the measured volume of one mole of the solid to obtain the number of molecules per molar volume.

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Avogadro's number

Number of units in one mole of any substance (defined as its molecular weight in grams), equal to 6.0221367 × 10²³. The units may be electrons, atoms, ions, or molecules, depending on the nature of the substance and the character of the reaction (if any). See also Avogadro's law; law of mass action; stoichiometry.