Answer;
(4) the total number of protons and the total number of electrons in the atom
Explanation;
-Atomic number is the number of protons in the nucleus of an atom. An atom is made up of energy shells and the central nucleus. The energy shells contains electrons that are negatively charged while the nucleus contains protons (positively charged) and neutrons (neutral).
-In a neutral atom, the number of protons and electrons are equal, thus the atomic number would indicate the number of electron and protons in an atom. The sum of protons and neutrons on the other hand gives the mass number.