Mole concept


  • Mole is a link between the mass of atoms (or molecules) and the number of atoms (or molecules).
  • One gram atom of any element contains the same number of atoms and one gram molecule of any substance contains the same number of molecules.
  • This number has been experimentally determined and found to be equal to 6.022137 × 1023 correct up to 7 significant figures.
  • This value was given by Amedeo Avogadro and is called as Avogadro number. The value is generally used as 6.022 × 1023 denoted by NA or N.
  • The amount of substance containing Avogadro’s number of atoms or molecules is called a mole.
  • A mole is chemists unit for counting entities at the microscopic level, such as atoms, molecules, ions, electrons, protons, neutrons, etc.
  • Thus, one mole is defined as the amount of a substance that contains as many entities or particles as there are atoms in exactly 12 g (or 0.012 kg) of the C12 isotope.