When does copper turn green????

Question

How long does it become green?

Answer 1

well if its in a dry area, it can take a while to turn green. copper becomes green when moisture causes it to corrode. its a chemical reaction, just like when iron becomes iron oxide(rust) when exposed to water

Answer 2

Copper turns green when it oxidizes. Its the equivalent to rust on iron. The oxidization forms a partial barrier to prevent further 'rusting'.

Answer 3

The natural weathering of copper is a direct consequence of the corrosive attack of airborne sulfur compounds.  This leads to a gradual change in the surface color until equilibrium is reached and the change is stabilized.  The final color is different and depends on the location and local weather.  Salt, moisture, sunlight and orientation can affect the final color. In general, copper changes in hue from a natural salmon through a progression of russet browns, grays and finally to a blue-green or gray-green patina.

Answer 4

Actually copper turns blackish with exposure to oxygen and also green to exposure to moist air....

see this from wikipedia:

Pure water and air

Copper is a metal that does not react with water (H2O), but the oxygen of the air will react slowly at room temperature to form a layer of brown-black copper oxide on copper metal.



The Pourbaix diagram for copper in pure water, perchloric acid or sodium It can be seen that copper in "pure" water is more noble than hydrogen. As a result it does not corrode in oxygen free water and the corrosion rate in oxygenated water is low. hydroxide[12]It is important to note that in contrast to the oxidation of iron by wet air that the layer formed by the reaction of air with copper has a protective effect against further corrosion. On old copper roofs a green layer of copper carbonate, called verdigris or patina, can often be seen. Another notable example of this is on the Statue of Liberty.

hope this helps