Molecules have low melting points because they have which are easy to break?

Molecules have low melting points because they have which are easy to break?

• A. Weak intermolecular forces
• B. Strong covalent bonds
• C. Ionic bonds
• D. Metallic bonds

Answer: (A)

Melting point is governed by the strength of the forces between particles in a solid. In molecular substances, the attractions between whole molecules are weak intermolecular forces (London dispersion, dipole-dipole, hydrogen bonding). These are relatively easy to overcome with heat, so the solid melts at a low temperature. If the structure were held together by strong covalent bonds, or by ionic or metallic bonds, melting would require breaking much stronger attractions, giving a higher melting point. So the best description is weak intermolecular forces.

Melting point is governed by the strength of the forces between particles in a solid. In molecular substances, the attractions between whole molecules are weak intermolecular forces (London dispersion, dipole-dipole, hydrogen bonding). These are relatively easy to overcome with heat, so the solid melts at a low temperature. If the structure were held together by strong covalent bonds, or by ionic or metallic bonds, melting would require breaking much stronger attractions, giving a higher melting point. So the best description is weak intermolecular forces.