Question

why do ionic formula units usually have higher melting and boiling points than covalent compounds?
the intermolecular forces in ionic formula units are weaker than those in covalent compounds
covalent molecules have higher electron affinities than ionic molecules.
ionic bonds are stronger than covalent bonds
the intermolecular forces in covalent compounds are weaker than those in ionic formula units
covalent bonds are stronger than ionic bonds

Explanation:

Ionic formula units form crystal lattices held by strong electrostatic attractions (ionic bonds) between ions. Covalent compounds (molecular) are held by weaker intermolecular forces (e.g., London dispersion, dipole-dipole). Higher melting/boiling points require overcoming stronger forces, so ionic compounds need more energy due to their stronger bonding compared to intermolecular forces in covalent compounds.

Answer:

The intermolecular forces in covalent compounds are weaker than those in ionic formula units