Name an alloy of copper. State its chemical composition and any one use.

49 Name five methods of preventing rusting of iron. 49 What are the constituents of stainless steel? What are the special properties of stainless steel? 50 Explain why, when a copper object remains in damp air for a considerable time, a green coating is formed on its surface. What is this process known as? 51 How does the painting of an iron object prevent its rusting?