The number "6.022 x 10^23" is known as Avogadro's number. It represents the number of atoms, molecules, or particles in one mole of a substance. This constant is fundamental in chemistry, allowing scientists to convert between the mass of a substance and the number of particles it contains. In practical terms, if you have one mole of water (H₂O), it contains approximately 6.022 x 10^23 water molecules. This concept helps chemists understand and calculate reactions, making it easier to work with the tiny particles that make up all matter.