Question

Bronze is a mixture of:
A.$Pb + Sn$
B.$Cu + Sn$
C.$Cu + Zn$
D.$Zn + Pb$

Answer 1

Bronze is an alloy composed primarily of copper, usually with around $12 - 12.5$ per cent tin and sometimes with the inclusion of other metals (such as iron, manganese, nickel or zinc) and often non-metals or metalloids such as arsenic, phosphorus or silicon.

Complete answer:
There are many different bronze alloys, but typically modern bronze is $88\%$ copper and $12\%$ tin. Alpha bronze consists of the alpha solid solution of tin in copper. Alpha bronze alloys of $4 - 5\%$ tin are used to make coins, springs, turbines and blades. Two forms of bronze were commonly used: classic bronze, about $10\%$ tin, was used in casting; and mild bronze, about $6\%$ tin, was hammered from ingots to make sheets. Bladed weapons were mostly cast from classic bronze, while helmets and armor were hammered from mild bronze.
Bronzes are typically ductile alloys, considerably less brittle than cast iron. Typically bronze oxidizes only superficially. Once a copper oxide (eventually becoming copper carbonate) layer is formed, the underlying metal is protected from further corrosion. This can be seen on statues from the Hellenistic period. However, if copper chlorides are formed, a corrosion-mode called bronze disease will eventually completely destroy it.
So, the correct answer is (B) $Cu + Sn$.

Note:
Bronze, or bronze-like alloys and mixtures, were used for coins over a longer period. Bronze was especially suitable for use in boat and ship fittings prior to the wide employment of stainless steel owing to its combination of toughness and resistance to salt water corrosion. Bronze is still commonly used in ship propellers and submerged bearings.