Final answer:
The average atomic mass of a natural carbon sample would be closer to Carbon-12 due to its higher abundance. Carbon-12 is about 98.89% of natural carbon, leading to an average atomic mass of approximately 12 amu. Carbon-12 has 6 neutrons and Carbon-13 has 7 neutrons.
Step-by-step explanation:
The average atomic mass of a sample of carbon would be closer to the mass of the isotope Carbon-12 (12C) because Carbon-12 is much more abundant than Carbon-13 (13C). In most naturally occurring carbon samples, about 98.89% of the atoms are Carbon-12, which has a mass number of 12 and an atomic number of 6. The remaining 1.11% are Carbon-13, with a mass number of 13 and the same atomic number of 6 (not 12 or 13 as incorrectly stated in some options). Carbon-13 adds slightly to the overall average atomic mass of carbon, resulting in an average atomic mass slightly above 12 amu, typically listed as 12.011 on the periodic table.
The molar mass of naturally occurring carbon reflects this mixture of isotopes. Since most carbon atoms in a sample are Carbon-12, the average atomic mass is very close to the mass of Carbon-12. Any significant deviation from this would suggest a sample with a non-typical isotope ratio. When analyzing a sample where 6% of carbon atoms have a mass number greater than 12, one can conclude there is a slightly higher proportion of Carbon-13 or other heavier isotopes, but the average atomic mass will still be close to that of Carbon-12 due to its overwhelming abundance.
How many neutrons do carbon-12 and carbon-13 have, respectively?
Both isotopes of carbon have an atomic number of 6, which corresponds to the number of protons. To find the number of neutrons in an isotope, you subtract the atomic number from the mass number. Therefore, Carbon-12 (12C) has 6 neutrons (12 - 6 = 6), and Carbon-13 (13C) has 7 neutrons (13 - 6 = 7).