<P> Brass is a metallic alloy that is made of copper and zinc . The proportions of zinc and copper can vary to create different types of brass alloys with varying mechanical and electrical properties . It is a substitutional alloy: atoms of the two constituents may replace each other within the same crystal structure . </P> <P> In contrast, bronze is an alloy of copper and tin . Bronze and brass - in turn - may include small proportions of a range of other elements including arsenic, lead, phosphorus, aluminium, manganese, and silicon . </P>

Brass is a mixture of what two metals