Which of the following best describes Avogadro's number?

• A. The mass of one mole of a substance in grams
• B. The number of particles in one mole of a substance
• C. The volume occupied by one mole of a gas at STP
• D. The number of atoms in one gram of hydrogen

Answer: (B)

Verified step by step guidance

1. Understand that Avogadro's number is a fundamental constant in chemistry that relates the amount of substance to the number of particles it contains.
2. Recall that one mole of any substance contains exactly the same number of particles, whether they are atoms, molecules, or ions.
3. Recognize that Avogadro's number is defined as the number of particles in one mole of a substance, which is approximately \$6.022 \times 10^{23}$ particles per mole.
4. Distinguish Avogadro's number from other related concepts such as molar mass (mass of one mole in grams), molar volume (volume of one mole of gas at STP), and atomic mass units.
5. Conclude that the best description of Avogadro's number is 'The number of particles in one mole of a substance.'