* No new substances are formed: Grinding simply changes the size and shape of the matter. The chemical composition remains the same.
* Change is reversible: You can often reverse the change by pressing the ground particles back together (though not always perfectly).
* No energy is released or absorbed: Grinding is primarily a mechanical process, not a chemical one. While some energy might be required to grind, it's not indicative of a chemical reaction.
Example: Grinding a rock into sand. The sand is still made of the same minerals as the original rock, just in smaller pieces.
Exceptions: In some cases, grinding can lead to very small particles that exhibit different properties than the original material. This is due to increased surface area, which can influence reactivity. However, the underlying chemical composition is still the same.
Let me know if you'd like more examples!
