Key Concepts: Avogadro's Number

Core Definitions

• Avogadro's Number: 6.022 × 10²³ — the number of particles (atoms, molecules, ions) in one mole.
• Mole: The SI unit for amount of substance; 1 mole = 6.022 × 10²³ particles.
• Mole-to-Particles: Multiply moles × 6.022 × 10²³ to find the number of particles.
• Particles-to-Moles: Divide number of particles by 6.022 × 10²³ to find moles.
• Amedeo Avogadro: Italian scientist who contributed to molecular theory; the number is named after him.
• Universal Counting Unit: A mole relates microscopic particles to macroscopic measurable amounts.