Which statement best explains why ionic compounds conduct electricity when melted or dissolved but not when solid?

Which statement best explains why ionic compounds conduct electricity when melted or dissolved but not when solid?

• A. Because ions are mobile only when melted or dissolved
• B. Because electrons in covalent bonds move
• C. Because the lattice breaks into ions when heated
• D. Because covalent bonds loosen

Answer: (A)

The main idea is that for electricity to flow, charged particles must be able to move. Ionic compounds are made of ions held together in a rigid lattice. In the solid state these ions are stuck in place, so they can’t carry charge, and the substance doesn’t conduct. When melted or dissolved, the lattice breaks apart and the ions become free to move. Their movement carries the electric current, so conduction occurs. The other statements aren’t right because conduction in ionic compounds isn’t about electrons in covalent bonds moving, and it isn’t about covalent bonds loosening. Melting or dissolving doesn’t rely on electrons moving between atoms; it relies on the ions themselves becoming mobile to carry charge.

The main idea is that for electricity to flow, charged particles must be able to move. Ionic compounds are made of ions held together in a rigid lattice. In the solid state these ions are stuck in place, so they can’t carry charge, and the substance doesn’t conduct. When melted or dissolved, the lattice breaks apart and the ions become free to move. Their movement carries the electric current, so conduction occurs.

The other statements aren’t right because conduction in ionic compounds isn’t about electrons in covalent bonds moving, and it isn’t about covalent bonds loosening. Melting or dissolving doesn’t rely on electrons moving between atoms; it relies on the ions themselves becoming mobile to carry charge.