Answer
The mass in grams of 1 mole of carbon is 12 grams.
Work Step by Step
This is because when one has one mole of any pure substance, that substance will weigh the same amount as it's atomic weight; however, this weight will be in grams. For example the following conversion can be used:
1 mol of carbon atoms X (12 grams Carbon)/(1 mol of Carbon)
Moles of carbon cancels with moles of carbon in the denominator and you're left with 12 grams of carbon.
