IB Chemistry SL Practice Exam 2026 – Complete Prep Resource

Avogadro's number is defined as the number of entities (which can be atoms, molecules, or ions) in one mole of a substance. It is a fundamental constant in chemistry that allows chemists to relate the macroscopic scale of substances (which we can measure in grams) to the atomic or molecular scale (where quantities are counted in terms of individual atoms or molecules).

The established value of Avogadro's number is 6.022 × 10^23. This number is a key figure in stoichiometry, facilitating calculations regarding the amounts of reactants and products in chemical reactions. The value reflects the number of particles present in one mole of any substance, making it essential for converting between the number of particles and the amount of substance in moles.

Other values listed in the options do not correspond to Avogadro's number and are either too high or too low, making them unsuitable for calculations involving moles of substances. Thus, 6.022 × 10^23 is the accepted and widely used value for Avogadro's number in the field of chemistry.