define mole

A mole is the amount of pure substance containing the same number of chemical units as there are atoms in exactly 12 grams of carbon-12 (i.e., 6.023 X 1023). This involves the acceptance of two dictates -- the scale of atomic masses and the magnitude of the gram. Both have been established by international agreement. Formerly, the connotation of "mole" was "gram molecular weight." Current usage tends to apply the term "mole" to an amount containing Avogadro`s number of whatever units are being considered. Thus, it is possible to have a mole of atoms, ions, radicals, electrons, or quanta. This usage makes unnecessary such terms as "gram-atom," "gram-formula weight," etc.

one mole is the amount of substance that contains as many particles or entities as there are in exactly one twelfth the mass of a carbon-12 isotope. Just like 1 dozen apples=12 apples similarly 1 mole of atoms=6.022 X 10^23 atoms.one mole can be any substance like atoms,molecules,ions,electrons etc. Here 6.022 X 10^23 is called Avogadro`s number and is represented by N subscript A.