Which of the following represents the number of particles in one mole of a substance?

The correct answer is 6.022 x 10^23, which represents Avogadro's number. This value defines the number of atoms, molecules, or other particles in one mole of a substance. This concept is fundamental in chemistry, as it allows chemists to count and convert amounts of a substance in practical laboratory settings.

For example, when balancing chemical reactions or converting between grams and moles, utilizing Avogadro's number helps relate the macroscopic quantities of substances to the number of particles involved. Knowledge of Avogadro's number is essential for stoichiometry, enabling accurate predictions of product formation and reactant consumption in chemical reactions.

This illustrates how a mole serves as a bridge between the atomic scale and the macroscopic scale, making laboratory work more feasible and allowing for consistent measurement in different chemical contexts.