Final answer:
The question involves evaluating the factors that affect lattice energies and melting points of ionic compounds, as well as predicting which chemical reactions will or will not occur based on the periodic table's reactivity sequence.
Step-by-step explanation:
The student's question appears to be related to ionic bonds and the factors that influence lattice energy in ionic compounds. Generally, ionic compounds with smaller, more highly charged ions have larger lattice energies because the electrostatic attraction between the ions is stronger. When comparing the potential lattice energy of chloride salts, those formed with smaller or more highly charged cations would be expected to have larger lattice energies. Similarly, when considering the melting points of oxides, those with stronger ionic bonds (again, small and highly charged ions) would typically have higher melting points.
When looking at which reactions would and would not take place, it is often determined by the relative reactivity or placement within the periodic table. In general, a more reactive halogen can displace a less reactive halogen from its compounds. Therefore, the statement that 'because iodine is below chlorine on the periodic table, a single-replacement reaction will not occur' relates to this reactivity sequence.