Which bond type typically yields a material with high melting points and conducts electricity when molten?

Which bond type typically yields a material with high melting points and conducts electricity when molten?

• A. Covalent bonds; high melting points and conducts electricity when molten.
• B. Ionic bonds; high melting points and conducts electricity when molten.
• C. Metallic bonds; high melting points and conducts electricity when molten.
• D. Ionic bonds; low melting points and does not conduct electricity.

Answer: (B)

Ionic bonding creates a solid lattice of alternating positive and negative ions held together by strong electrostatic forces. This makes the lattice energy very large, so a lot of energy is needed to break the lattice and melt the solid, giving high melting points. In the solid state the ions are fixed in place, so there aren’t free charge carriers to conduct electricity. When the substance is melted, the ions are free to move, allowing electric current to flow. That combination—high melting points and conductivity when molten—is characteristic of ionic compounds, such as table salt (NaCl).

Ionic bonding creates a solid lattice of alternating positive and negative ions held together by strong electrostatic forces. This makes the lattice energy very large, so a lot of energy is needed to break the lattice and melt the solid, giving high melting points. In the solid state the ions are fixed in place, so there aren’t free charge carriers to conduct electricity. When the substance is melted, the ions are free to move, allowing electric current to flow. That combination—high melting points and conductivity when molten—is characteristic of ionic compounds, such as table salt (NaCl).