Final answer:
The mass number represents the total number of protons and neutrons in the nucleus of an atom, while the average atomic mass is the weighted average of the masses of all naturally occurring isotopes.
Step-by-step explanation:
In chemistry, the mass number refers to the total number of protons and neutrons in the nucleus of an atom. It is represented by the symbol A. For example, the mass number of carbon-12 is 12, indicating that it has 6 protons and 6 neutrons in its nucleus.
The average atomic mass, on the other hand, is the weighted average of the masses of all naturally occurring isotopes of an element. It takes into account the abundance of each isotope. It is represented by the symbol on the periodic table. For example, the average atomic mass of carbon is approximately 12.01, which takes into account the different isotopes of carbon.
Therefore, the main difference between the mass number and the average atomic mass is that the mass number is the actual value for a specific isotope, while the average atomic mass is an average value that considers the different isotopes and their abundances.
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