Question

What is the average mass of one mole of naturally occurring, pure carbon?

• A. $12.00g$ because isotopes are not present in a pure sample of an element and Carbon$-12$ is most abundant.
• B. $12.01g$ because different isotopes of carbon are present in a naturally occurring sample and $Carbon-12$ is most abundant
• C. The mass will vary because it depends on the amount of each allotrope of carbon the sample contains - diamond or graphite.
• D. $13.00g$ because three isotopes of carbon are present in the sample: $Carbon-12,Carbon-13$ and $Carbon-14$.

Answer 1

Answer: (B)

$12.01g$ because different isotopes of carbon are present in a naturally occurring sample and $Carbon-12$ is most abundant

$12.01g$ because different isotopes of Carbon are present in a naturally occuring sample and Carbon - 12 is abundant.

The average atomic mass represents the weighted average of all naturally occuring isotopes.