What is Avogadro's number?

• A. 6.022 x 10^23 grams = 1 mole
• B. 6.022 x 10^23 liters = 1 mole
• C. 6.022 x 10^23 particles is equal to 10 moles
• D. 6.022 x 10^23 particles = 1 mole

Answer: (D)

Avogadro's number is the number of discrete particles in one mole, providing the bridge between the microscopic world and macroscopic measurements. By definition, one mole contains 6.022 × 10^23 particles (atoms, molecules, or other entities, depending on the substance). This means the amount of substance in moles times Avogadro's number gives the total number of particles: N = n × Na, with Na = 6.022 × 10^23 mol^-1. So 1 mole equals 6.022 × 10^23 particles. The other statements mix up units or scales: grams are a mass, liters a volume, and 10 moles would contain 6.022 × 10^24 particles, not 6.022 × 10^23.