when copper is exposed to the air, it slowly turns green over a period of time. what type of change is occurring? can anyone explain.
2007-06-25 09:23:13 · 3 answers · asked by princess 2 in Science & Mathematics ➔ Chemistry
It oxidizes in air oxygen and carbon dioxide to form a "basic copper carbonate," Cu(OH)2*CuCO3. On bronze statues and copper rooves, this is called patina.
2007-06-25 09:30:54 · answer #1 · answered by steve_geo1 7 · 0⤊ 0⤋
copper carbonate is one answer.
If the statue is near the sea, as in the Statue of Liberty, it also reacts with the salt in the air to make copper chloride, a blue compound on the surface. These are chemical changes.
changes which show a color change are chemical.
2007-06-25 17:06:48 · answer #2 · answered by science teacher 7 · 0⤊ 0⤋
I think the answer to that would be a physical change because you can see that it was once copper color and then green now.....Try that one
2007-06-25 17:01:27 · answer #3 · answered by Anonymous · 0⤊ 1⤋