Question

Distinguish between mass number vs. atomic number; define isotopes

Answer 1

Mass number is the sum of proton and netron numbers of an element while Atomic number is the number of protons in an atom.

Isotope are atoms of the same element that have the same atomic number but different in mass number.

Answer 2

Mass number refers to the number of nucleons in an atom whereas atomic number refers to the number of protons in the atom's nucleus

isotopes are atoms of the same element with the same atomic number but different mass number due to difference in number of neutrons