Question

describe the relationship between mass number and atomic number​

Answer 1

mass number = no of protons + number of neutrons

mass number = atomic number + number of neutrons

diatomic number and mass number can be an element with atomic number is written on the lower left side of the symbol whereas mass number is written on the upper left side of the symbol of the element

Answer 2

Mass number = no. of protons + no. of neutrons
since , the number of protons present in an atom is represented by the term ' atomic number',
so we can replace 'atomic number ' in place of ' no . of protons '
We get :
Mass number = atomic number + no . of neutrons.
hope it helps u