Final answer:
The more stable anion is typically formed by nonmetals at the top of groups or in group 17 due to their high electronegativity and tendency to satisfy the octet rule. In metal complexes, stability increases with more electrons in the t2g orbitals. Lattice energy also contributes to ionic compound stability, with higher lattice energy indicating stronger ionic bonding.
Step-by-step explanation:
To identify the more stable anion, we can apply certain principles from periodic trends and molecular orbital theory. Looking at the periodic table, we can see that the stability of an anion increases with the nonmetal's strength as an oxidizing agent. Nonmetals in the top of a group or in group 17 (halogens) typically form the most stable anions because they have a high electronegativity and a greater tendency to gain electrons to obtain a noble gas configuration, satisfying the octet rule.
When comparing complexes with the same metal ion and oxidation number, the stability of the complex is higher when the number of electrons in the t2g orbitals is greater. This is due to the crystal field stabilization energy (CFSE) provided by the filled t2g orbitals, leading to a more stable electron arrangement.
Moreover, factors like lattice energy also play a significant role in the stability of ionic compounds. A higher lattice energy is indicative of a more stable ionic compound, often resulting from smaller ionic sizes and higher charges on the ions. ZnO, for example, has a larger lattice energy compared to NaCl due to the higher charge and smaller ionic radius of Zn2+ compared to Na+ and O2- compared to Cl-.