Properties of ionic compounds Original Scenario-Based Download PDF

Questions

1. 1.

   During an expedition to an uncharted geothermal rift, researchers recover a translucent crystalline mineral named Litho-X that features an exceptionally high melting temperature. Laboratory tests reveal that solid Litho-X behaves as an electrical insulator, yet melting the crystal into a liquid or dissolving it in water allows it to readily conduct electric current, while striking the solid with a chisel causes it to shatter cleanly along flat planes rather than bend. Which microscopic explanation correctly accounts for this electrical behavior and the pronounced brittleness of the mineral?

   • A) In the solid lattice, ions are locked into fixed positions, but melting frees these charged particles to migrate under an applied voltage, whereas mechanical impacts shift ion layers so that ions of like charge align and repel each other violently.
   • B) Delocalized valence electrons are immobilized in directional covalent bonds throughout the solid state and only become conductive mobile carriers once thermal energy breaks all chemical bonds completely.
   • C) Discrete neutral molecules inside the crystalline framework ionize into free radicals in the molten state, while mechanical force causes intermolecular dipole attractions to temporarily collapse without electrostatic repulsion.
   • D) Metal cations migrate freely through interstitial gaps in the solid crystal to provide conductivity, but an external impact permanently closes these channels and traps migrating electrons.