* Avogadro's Number: The key to this calculation is Avogadro's number, which tells us the number of particles (atoms, molecules, etc.) in one mole of a substance. Avogadro's number is approximately 6.022 x 10^23.
* Molecules in a Mole: Since one mole of any substance contains Avogadro's number of particles, one mole of NO2 contains 6.022 x 10^23 NO2 molecules.
Therefore, there are approximately 6.022 x 10^23 NO2 molecules in 1 mole of NO2.
