Question

The atomic mass of carbon is 12.011 amu. Does this mean that a carbon atom selected at random is likely to have a mass of 12.011 amu? Explain.

A) Yes, the atomic mass represents the average mass of carbon atoms in nature.
B) No, individual carbon atoms may have slightly different masses due to isotopic variations.
C) Yes, all carbon atoms have exactly the same mass of 12.011 amu.
D) No, the atomic mass is a theoretical value and may not correspond to the actual mass of any carbon atom.

Answer 1

The atomic mass of carbon is 12.011 amu, which is a weighted average of its isotopes; hence, a random carbon atom may not have this exact mass.

Step-by-step explanation:

The atomic mass of carbon is listed as 12.011 amu on the periodic table, which represents the weighted average of the masses of the naturally occurring isotopes. Carbon predominantly exists as ¹²C, accounting for approximately 98.89% of natural carbon and has a mass of exactly 12 amu by definition.

The remaining 1.11% primarily consists of the isotope ¹³C with a mass of 13.003355 amu. Therefore, a single carbon atom selected at random is not likely to have an exact mass of 12.011 amu due to the presence of isotopes. The correct answer is B) No, individual carbon atoms may have slightly different masses due to isotopic variations.