Final answer:
The atomic mass of an element represents the average atomic weight, which is the weighted average of the masses of all the isotopes of an element.
Step-by-step explanation:
The atomic mass of an element provides information about the average atomic weight of all the isotopes of that element as they occur naturally. The atomic mass takes into account the relative abundance of each isotope and its mass.
The correct answer is C) Average atomic weight. It reflects the average number of protons and neutrons in the nucleus of the atom, as the electrons contribute negligibly to an atom's weight. The atomic mass is not used directly to determine the number of protons, electrons, or neutrons in an atom; however, since the atomic number represents the number of protons, you can find the average number of neutrons by subtracting the atomic number from the atomic mass.