Mole Concept - Some Basic Concepts of Chemistry - Class 11 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. The value was found to be 6.022137 × 1023 The value generally used is 6.022 × 1023 . This is called Avogadro's number or Avogadro's constant (NA) Avogadro's … [Read more...] about Mole concept