Chemistry Regents Practice Test 2026 - Free Chemistry Regents Practice Questions and Study Guide

Avogadro's number, which is approximately \(6.022 \times 10^{23}\), represents the quantity of constituent particles (which can be atoms, molecules, or ions) contained in one mole of a substance. This fundamental constant allows chemists to convert between the number of moles and the number of individual particles, facilitating calculations in chemical reactions and stoichiometry.

Understanding this concept is crucial for working with moles, as it provides a bridge between the macroscopic quantities that can be measured in the laboratory and the microscopic amount of particles which govern chemical behavior. For example, one mole of water contains \(6.022 \times 10^{23}\) water molecules, demonstrating how Avogadro's number serves as a foundational tool in quantifying chemical substances in practical scenarios.

The other options do not align with the definition of Avogadro's number. While some relate to concepts associated with moles or atomic quantities, they do not directly define what Avogadro's number itself signifies.