Final answer:
The nuclear charge of Na+ is +11, reflecting its 11 protons, and the ion has a +1 overall charge due to having one fewer electron than protons. The nuclear charge of S-2 is +16, which is the number of protons in the sulfur nucleus, and the ion has a -2 overall charge because it has two more electrons than protons.
Step-by-step explanation:
The nuclear charges for S-2 and Na+ ions are determined by the number of protons they contain because the nuclear charge is equivalent to the number of protons in the nucleus of an atom or ion. A neutral sodium (Na) atom has 11 protons and 11 electrons, resulting in a net charge of zero. However, when sodium becomes a cation, as in Na+, it loses an electron and therefore has 10 electrons while still having 11 protons. As a result, the nuclear charge for Na+ is +11 due to its 11 protons, which also gives it a +1 overall charge since it has one more proton than electrons.
As for the S-2 ion, which is a sulfide ion, the sulfur atom originally has 16 protons and 16 electrons, hence a neutral charge. When it gains two electrons to become S-2, it has 18 electrons and 16 protons. Notwithstanding the extra electrons, the nuclear charge remains at +16 corresponding to the number of protons. Thus, the sulfide ion has a -2 overall charge due to having two more electrons than protons.