Final answer:
Avogadro's number, approximately 6.022 x 10²³, represents the number of particles in one mole of any substance and is essential for relating atomic-scale measurements to macroscopic ones in chemistry.
Step-by-step explanation:
Avogadro's number is a fundamental constant in chemistry that represents the number of particles (atoms or molecules) in one mole of a substance. The value of Avogadro's number is approximately 6.022 x 10²³, which is the number of particles found in one mole of any substance. This number is significant because it bridges the gap between the microscopic scale of atoms and molecules and the macroscopic scale that we experience in everyday life. When you weigh out a substance in grams equal to the molecular mass, you would have exactly one mole of the substance, which contains Avogadro's number of particles.