* Chemical Change: Involves the formation of new substances with different chemical properties.

* Physical Change: Only alters the appearance or state of matter, not the chemical composition.

The Reaction:

When green copper carbonate (CuCO₃) is heated, it decomposes into black copper oxide (CuO), carbon dioxide (CO₂), and water (H₂O).

Equation:

CuCO₃ (green) → CuO (black) + CO₂ + H₂O

Key Points:

* New substances: Copper oxide, carbon dioxide, and water are formed, which are different from the original copper carbonate.

* Chemical composition changed: The arrangement of atoms has changed, resulting in new substances.

* Irreversible: You cannot easily reverse the process to get back the original copper carbonate.

Therefore, the change in color and the formation of new substances indicate a chemical change has occurred.