Why is the atomic number considered a better fundamental attribute of an element than the mass number? State the reason.

(N/A) The atomic number is considered a more fundamental attribute because it represents the number of protons in the nucleus of an atom,which uniquely defines the identity of an element.
Unlike the mass number,which can vary due to the presence of different numbers of neutrons (isotopes),the number of protons remains constant for all atoms of a specific element.
Furthermore,the chemical properties of an element are primarily determined by its electronic configuration,which is directly dictated by the atomic number (number of protons/electrons in a neutral atom).