Avogadro’s number, number of units in onemoleof any substance (defined as itsmolecular weightin grams), equal to 6.02214076 × 1023. The units may beelectrons,atoms,ions, ormolecules, depending on the nature of
Themolecular weightof a molecule is the sum of theatomic weightsof its component atoms. If a substance has molecular weightM, thenMgramsof the substance is termed onemole. The number of molecules in one mole is the same for all substances; this number is known asAvogadro’s number(6.022140...
(this is called the molar mass) and represents 6.022140857 × 1023atoms (Avogadro’s number). One mole of iron contains 55.847 grams; one mole of methane contains 16.043 grams; one mole of molecular oxygen is equivalent to 31.999 grams; and one mole of water is 18.015 grams. Each of ...