Final answer:
To determine the compound with the lowest lattice energy among NaCl, KF, CaO, and MgO, we need to consider the charges and sizes of the ions. Comparing the charges and sizes, we can see that MgO has the highest charges (+2 and -2) and the smallest ion sizes, making it the compound with the highest lattice energy among the given options. Therefore, MgO is predicted to have the lowest (least negative) lattice energy.
Step-by-step explanation:
The lattice energy of an ionic compound depends on the charges and the sizes of the ions. In general, the compound with the highest charges and smallest ion sizes will have the highest lattice energy. Therefore, to determine the compound with the lowest lattice energy among NaCl, KF, CaO, and MgO, we need to consider the charges and sizes of the ions.
Among the given compounds:
- NaCl: Na+ has a charge of +1 and Cl- has a charge of -1.
- KF: K+ has a charge of +1 and F- has a charge of -1.
- CaO: Ca2+ has a charge of +2 and O2- has a charge of -2.
- MgO: Mg2+ has a charge of +2 and O2- has a charge of -2.
Comparing the charges and sizes of the ions, we can see that MgO has the highest charges (+2 and -2) and the smallest ion sizes, making it the compound with the highest lattice energy among the given options.
Therefore,
MgO
is predicted to have the lowest (least negative) lattice energy.