Answer
A.
Work Step by Step
Two atoms behave differently only when the number of electrons they have differs.The chemical properties of all atoms are determined by the number of electrons, not by the number of protons or neutrons. Protons and neutrons are present inside the nucleus of an atom, and the nuclei of two atoms are too far from each other to influence the chemical properties of each other. It's because of this reason that isotopes of an element do not have different chemical properties. Isotopes of an element show the same chemical behavior because they have the same number of electrons. (Isotopes of an element have a different number of neutrons, but it does not influence their chemical behavior.)
