Avogadro's number is approximately which value?

• A. 6.02 x 10^21
• B. 6.02 x 10^23
• C. 12.00
• D. 1.00

Answer: (B)

Avogadro’s number tells you how many individual particles are in one mole of a substance, linking the amount you weigh to the actual number of atoms or molecules. The standard value is about 6.022 × 10^23 particles per mole, so it’s common to round to 6.02 × 10^23. This is the reason a mole of carbon-12 weighs 12.00 g: one mole (6.022 × 10^23 atoms) has a mass equal to the substance’s molar mass in grams per mole.

The other numbers don’t fit because 6.02 × 10^21 is missing two powers of ten and would represent far fewer particles per mole; 12.00 is the mass in grams per mole for carbon-12, not a count of particles; and 1.00 is just a simple unitless value, not a particle count.