Which species have the same number of electrons?I. S2–II. Cl–III. NeA.I and II onlyB. I and III onlyC. II and III onlyD. I, II and III

To answer this question, we need to know the atomic number of each species, which represents the number of protons and, in a neutral atom, also the number of electrons.

I. S2–: Sulfur (S) has an atomic number of 16, so a neutral S atom would have 16 electrons. However, S2– indicates that this ion has gained 2 extra electrons, so it has 18 electrons.

II. Cl–: Chlorine (Cl) has an atomic number of 17, so a neutral Cl atom would have 17 electrons. However, Cl– indicates that this ion has gained 1 extra electron, so it has 18 electrons.

III. Ne: Neon (Ne) has an atomic number of 10, so a neutral Ne atom would have 10 electrons.

Therefore, S2– and Cl– have the same number of electrons (18), but Ne does not. So, the correct answer is A. I and II only.