Avogadro’s number, denoted as NA, is the number of particles in one mole of a substance. This number is approximately equal to 6.022 x 1023, which is a huge number.
The particles can be atoms, molecules, ions, or electrons, depending on the substance. For example, one mole of oxygen gas contains 6.022 x 1023 oxygen molecules, while one mole of sodium ions contains 6.022 x 1023 sodium ions.