Chemical changes Original Scenario-Based Download PDF

Questions

1. 1.

   While exploring a cavern on an uncharted moon, a planetary surveyor drops a clear nutrient droplet onto a dense crystalline shard. The contact zone immediately begins bubbling vigorously, releases a plume of pungent crimson vapor, warms the surrounding glass container, and leaves behind an insoluble slate-gray crust. Which statement correctly identifies why this interaction represents a chemical change rather than a physical change?

   • A) The liquid droplet changed its shape and spread uniformly across the crystalline surface.
   • B) New substances formed, as demonstrated by gas production, thermal energy release, and an irreversible change in chemical identity.
   • C) The crystalline shard melted into a liquid state purely because of mechanical pressure from the droplet.
   • D) The crystal simply dissolved into the nutrient droplet and could be fully reconstituted by gentle evaporation.