define atomic mass number. what is the relationship between

define atomic mass number. what is the relationship between
Answer
Brief Explanations:
Atomic mass number is the sum of protons and neutrons in an atom's nucleus. It represents the total number of nucleons. It is a whole - number value and is used to distinguish different isotopes of an element.
Answer:
The atomic mass number is the sum of the number of protons and neutrons in the nucleus of an atom.