When copper turns green, it is typically due to a chemical change. This color change occurs as copper reacts with oxygen and moisture in the environment, resulting in the formation of copper oxide or, more commonly, copper carbonate (often seen as patina).
In general:
- Physical Properties are characteristics that can be observed or measured without changing the substance's chemical identity (e.g., color, melting point, boiling point).
- Chemical Properties describe a substance's ability to undergo changes that transform it into different substances (e.g., reactivity with oxygen).
Thus, the change in color of copper to green is a result of a chemical change because it involves the formation of new substances.