Verdigris.
Copper cloride is the word equation for copper and clorine hope this helps:)
When copper and oxygen react, they combine to form copper(II) oxide. This chemical reaction involves the transfer of electrons from copper to oxygen, resulting in the formation of the compound CuO. Copper(II) oxide is a black solid.
Iron corrodes faster than copper because iron is more susceptible to oxidation in the presence of moisture and oxygen, leading to the formation of rust. Copper, on the other hand, forms a protective layer of copper oxide (patina) on its surface that slows down the rate of corrosion.
"Copper mailboxes will make your neighbor's envious. They will not rust, they are extremely attractive, and go along with any type home. Year after year you will have great service from them."
The green material on copper is oxidation. On iron or steel it is called rust, on copper and bronze is it called a patina. Unlike the rust on steel and iron that damages the metal, rust on copper, bronze, and even aluminum can protect the under-laying metal. You can even make the green different shades by applying different oxidizers, which some artists use in place of painting the metal.
by me
Copper doesn't rust
Copper corrodes, things made of iron rust. Copper can corrode, but it takes longer than it does for iron to rust.
Rust occurs on iron and steel when they oxidize in the presence of moisture and oxygen. Copper does not rust; instead, it forms a patina when it oxidizes, which is a greenish layer that protects the copper from further corrosion.
Plastic pipe does not rust, brass does not rust, copper does not rust. Stainless steel does not rust, lead pipe does not rust.
The only chemical that could make something rust is iron; "rust" refers specifically to the corrosion of iron, so copper cannot rust. However, its corrosion is caused by copper itself being oxidised and forming compounds which are water soluble and also easier to damage.
Oxygen turns copper green.
copper does not rust
Most likely some other object has dripped rust onto the copper, which can be removed. Copper does not rust, but it does form a green patina over time.
Copper does not rust; it develops a greenish film called patina when exposed to air and moisture. The formation of patina can take several years, depending on the environmental conditions.
copper turns to blue-green copper oxide.
Copper forms a green rust known as basic copper carbonate or malachite when exposed to oxygen and moisture over time.