One mole of carbon atoms contains how many carbon atoms?

• A. 3.01 x 10^23
• B. 1.20 x 10^24
• C. 6.02 x 10^23
• D. 12 carbon atoms

Answer: (C)

A mole is a counting unit equal to Avogadro’s number of particles. For carbon, one mole contains 6.02×10^23 carbon atoms. The other numbers are off by about a factor of two or describe a different concept (12 refers to the atomic mass in amu, not a count of atoms). So the correct value is 6.02×10^23 carbon atoms per mole.