Final answer:
Avogadro's number is a fundamental constant in chemistry indicating the number of particles in one mole, which is accurately 6.022 × 10²³.
Step-by-step explanation:
Avogadro's number, denoted as NA, is the number of particles, such as atoms or molecules, contained in one mole of a substance. The correct value for Avogadro's number is 6.022 × 10²³ particles per mole, which means that option c, NA = 6.022 × 10²³, is the correct answer. As such, it is a crucial constant in chemistry for converting between the number of particles and the amount of substance in moles.