A pure white solid material that looks like table salt releases gas when heated under certain conditions. There is no change in the appearance of the solid, but the reactivity of the material changes.

Question

A pure white solid material that looks like table salt releases gas when heated under  certain conditions.  There is no change in the appearance  of the solid, but the reactivity of the material changes.

Did a chemical or physical change occur? How do you know?

Was the original material an element or a compound?

DrBob222 · Accepted Answer

A chemical change occurred. A gas was released and not all of the compound decomposed. It was a compound since a gas was evolved and that wasn't all of the material.