Final answer:
The mass number represents the total number of nucleons in the nucleus, including protons and neutrons. The atomic number represents the number of protons in the nucleus. Both numbers provide valuable information about the composition of an atom's nucleus.
Step-by-step explanation:
The mass number and atomic number are both considered nuclear numbers because they provide information about the composition of an atom's nucleus.
The atomic number (Z) represents the number of protons in the nucleus. This number is unique to each element and helps distinguish one element from another.
The mass number (A) represents the total number of nucleons in the nucleus, which includes the sum of protons and neutrons. It is used to determine the number of neutrons by subtracting the atomic number from the mass number.