Which of the following is closest to the atomic mass of carbon?

• A. 14.01 amu
• B. 16.00 amu
• C. 10.81 amu
• D. 12.01 amu

Answer: (D)

Verified step by step guidance

1. Understand that the atomic mass of an element is the weighted average of the masses of its naturally occurring isotopes, measured in atomic mass units (amu).
2. Recall that carbon has two main stable isotopes: carbon-12 and carbon-13, with carbon-12 being the most abundant.
3. Recognize that the atomic mass listed on the periodic table reflects this weighted average, which is close to but not exactly the mass of the most abundant isotope.
4. Compare the given options to the known average atomic mass of carbon, which is approximately 12.01 amu.
5. Identify that among the options, 14.01 amu and 16.00 amu correspond to other elements (nitrogen and oxygen), and 10.81 amu corresponds to boron, so 12.01 amu is the closest to carbon's atomic mass.