Answer:
The atomic mass of carbon-12 is exactly 12.
Step-by-step explanation:
12.011 amu
All the masses of the elements are determined relative to 12C. Since many elements have a number of isotopes, chemists use average atomic mass. On the periodic table the mass of carbon is reported as 12.011 amu.
OR
The relative atomic mass of carbon-12 is defined as exactly 12 and the relative atomic mass of carbon-13 is 13.00335. Now, you can calculate the atomic weight of carbon in the sample. For this sample, the atomic weight of carbon is 12.0107.