The correct answer is 6.022 × 10^(23). Explanation & Key Takeaways: • Avogadro's constant, also known as Avogadro's number, is named after the Italian scientist Amedeo Avogadro. • It is defined as the number of constituent particles (usually atoms or molecules) that are contained in one mole of a substance. • The value of Avogadro's constant is 6.022 × 10^(23) mol^(-1). • Avogadro's constant is a fundamental constant in chemistry and physics that allows chemists to count the number of atoms, ions, or molecules in a given sample. Related Concepts: • Avogadro's Law: • Avogadro's law states that equal volumes of all gases, at the same temperature and pressure, have the same number of molecules. • This law provides the relationship between the volume of a gas and the amount of substance of the gas present. • The Mole Concept: • The mole is a unit of measurement for the amount of substance in the International System of Units (SI). • One mole contains exactly 6.02214076 × 10^(23) elementary entities (Avogadro's constant). • This concept is used to convert between the number of particles and the amount of substance. • Importance in Chemistry: • Avogadro's constant is crucial for understanding and working with chemical reactions, as it allows chemists to determine the number of particles involved. • It is essential for calculations involving the ideal gas law, stoichiometry, and other chemical principles. • Historical Context: • Amedeo Avogadro (1776-1856) was an Italian scientist who made significant contributions to molecular theory. • Avogadro's hypothesis, proposed in 1811, led to the eventual development of the concept of the mole and Avogadro's constant.