Final answer:
One mole of carbon atoms weighs 12.0 grams.
Step-by-step explanation:
One mole of carbon has a mass of 12.0 g since it is nearly pure 12C. The number of carbon atoms in a mole is equal to Avogadro's number, which is 6.022 × 10^23. Therefore, a mole of carbon atoms would weigh 12.0 grams.