How is an atom's atomic mass number determined? how is an atom's atomic mass number determined? the atomic mass number is determined only by the number of alpha particles emitted. the atomic mass number is determined only by the number of neutrons in the nucleus. the atomic mass number is determined only by the number of nucleons in the nucleus. the atomic mass number is determined only by the number of beta particles emitted. the atomic mass number is determined only by the number of protons in the nucleus. the atomic mass number is determined only by the number of electrons in the atom. request answer provide feedback

The atomic mass number is determined only by the number of nucleons in the nucleus

Explanation:

Atomic number is defined as the number of protons or electrons that are present in a neutral atom.  It is represented by the symbol 'Z'

Atomic number = number of protons = number of electrons

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.  It is represented by the symbol 'A'

Mass number = Number of protons + Number of neutrons

Nucleons are defined as the sub-atomic particles which are present in the nucleus of an atom. Nucleons are protons and neutrons.

Hence, the atomic mass number is determined only by the number of nucleons in the nucleus