Question

The composition of bell metal is:
A. $Cu(80\% ),\,Zn(20\% )$
B. $Cu(60\% ),\,Ni(40\% )$
C. $Cu(90\% ),\,Sn(10\% )$
D. $Cu(80\% ),\,Sn(20\% )$

Answer 1

Hint – The "Bell-metal" is a form of bronze (an alloy consisting primarily of copper and other metals) that has a higher tin content, usually in approximately a 4:1 ratio of copper to tin.

Complete step-by-step answer:
Let us first understand what an alloy is: ‘Alloy’ is defined as a metallic substance that is composed of two or more elements, as either a compound or a solution. The components of alloys are commonly themselves metals, though carbon, which is a non-metal, is a primary constituent of steel.
Tin and copper are relatively softer metals that will deform on striking, but alloying these two elements creates a metal that is harder and less ductile and also has more elasticity than either copper or tin. This metal combination produces a robust, long-wearing material that is resistant to oxidation.
Another interesting fact of this alloy is: The higher tin content in the alloy increases the rigidity of the metal and increases its resonance as well. These alloys are known as ‘bell-metals’ because they give a pleasing sound when struck with some force.
Now coming back to the question where it is asked what is the composition of bell metal. As mentioned earlier as well bell metal is an alloy in approximately a 4:1 ratio to tin, thus the bell metal is composed of 80% Copper and 20% Tin i.e. ($Cu(80\% ),\,Sn(20\% )$
Therefore option D is correct.

Note – Bell metal as the name itself suggests is used for making bells as the particular combination of copper and tin gives strength and resistance to abrasions. This combination gives a particular 'clang' sound which is clear and distinct when struck. Bell metal is also used in the manufacturing of utensils.