Question

Compared with ionic compounds, molecular compounds


are harder


have higher boiling points


are brittle


have lower melting points

Answer 1

Correct choice: have lower melting points.

Explanation:
- Molecular (covalent) compounds are held together in the solid state by relatively weak intermolecular forces (van der Waals, dipole–dipole, hydrogen bonding), whereas ionic compounds are held by strong electrostatic attractions in a rigid lattice. That makes molecular solids generally softer and have much lower melting and boiling points than ionic solids.
- So: "are harder" — no (usually softer). "have higher boiling points" — no (usually lower). "are brittle" — no (brittleness is a characteristic of ionic crystals). "have lower melting points" — yes.