Final answer:
MgF2 should have the highest melting point among the given compounds due to its stronger lattice energy resulting from the smaller ionic radii and higher charge of Mg2+ and F- ions.
Step-by-step explanation:
To determine which compound has the highest melting point, one must consider the strength of the intermolecular forces. Ionic compounds generally have higher melting points due to the strong electrostatic attraction between oppositely charged ions. Among the given compounds (MgF2, SrCl2, SrF2, SrI2, and BaCl2), MgF2 is expected to have the highest melting point. This is because Mg2+ has a higher charge than Sr2+ or Ba2+, and F- is smaller in size than Cl- or I-, resulting in a stronger lattice energy due to the smaller ionic radii and higher charge of Mg2+ and F-.