The chemical symbol for copper is Cu, from the Latin 'cuprum', meaning from Cyprus, from where the Romans obtained much of their copper. Copper has the Atomic Number 29 (the number of protons in an atom) and is in the group called 'Transition Metals' in the Periodic Table.
All common metals and alloys react with a moist atmosphere and corrode. Only in hot/dry (deserts) and cold/dry environments do metals resist corrosion. However, with copper the corrosion process is very slow. The corrosion resistance of copper and copper alloys is based on their ability to form stable compounds that provide some protection from corrosive attack. When exposed to the atmosphere, protective layers of oxides and poorly soluble basic salts form on the surface of copper and copper alloys. Suitable alloying elements can positively influence the formation of these coatings.
Copper is in the same periodic table group as silver and gold. Therefore, it is relatively inert against chemicals. In most of its compounds it can have the valency (oxidation state) of +I or the valency state +II. The aqueous solutions of copper ions in the oxidation state +II have a blue colour, whereas copper ions in the oxidation state +I are colourless. Copper and copper compounds give a greenish colour to a flame.