Question

the crystal structure of nabr is represented in the diagram above. which statement correctly compares crystalline nabr(s) to molten nabr(l) in terms of electrical conductivity?
(a) crystalline nabr contains no freely moving electrons that could conduct an electrical current, whereas electrons can flow freely in molten nabr, which is a good conductor of electricity.
(b) crystalline nabr and molten nabr both contain ions that are held in fixed positions due to strong electrostatic attractions among the ions, making neither a good electrical conductor.
(c) crystalline nabr and molten nabr both contain na atoms that transfer electrons to br atoms in a chemical reaction, thus allowing them both to be good conductors of electricity.
(d) crystalline nabr contains no freely moving electrons to conduct electricity, but molten nabr is composed of freely moving na+ and br- ions, which allows it to be a good conductor of electricity.

Explanation:

Crystalline \( \text{NaBr} \) has ions in fixed positions due to strong electrostatic attractions, so ions can't move freely to conduct electricity. Molten \( \text{NaBr} \) has ions (\( \text{Na}^+ \) and \( \text{Br}^- \)) that are free - moving, allowing it to conduct electricity.

Answer:

D. Crystalline \( \text{NaBr} \) contains no freely moving \( \text{Na}^+ \) and \( \text{Br}^- \) ions, which allows it to be a good conductor of electricity.