Question

Bell-metal is the metal used for making bells for churches. This metal gives the bell its special ringing sound. What does it contain?
${\text{A}}{\text{.}}$ Copper and tin
${\text{B}}{\text{.}}$ Iron and lead
${\text{C}}{\text{.}}$ Nickel and zinc
${\text{D}}{\text{.}}$ Silver and antimony

Answer 1

Hint: Here, we will proceed by defining the metal bell. Then, we will write down the elements which will form the alloy of bell metal. Then, we will discuss the variation of range of the individual element.

Complete step-by-step answer:

Bell metal is a hard alloy used to make bells and related instruments. It is a type of bronze with a higher tin content, typically in a copper-to-tin ratio of approximately 4:1 (currently 78 percent aluminium and 22 percent tin by mass). The higher tin content increases metal stiffness, and the resonance increases. It also has industrial uses such as valve heads, piston rings, bearings and bushings.
Tin and copper are relatively soft metals that deform on striking (although tin to a lesser extent than copper), but alloying creates a metal that is harder and less ductile, and also one that has more elasticity than either of the two individual metals.
A range of tin content percentages that vary from 20 to 26 percent, depending on the creator who has met their own alloy ratio empirically. Increasing the tin content has been found to increase the decay time of the bell strike, making the bell more sonorous. Considering overall properties, such as tensile strength, hardness, wear resistance, cast quality, sound and cost, it is likely that the optimum alloy can be achieved.
Bell metal has been used for over 3000 years in this range of ratios, and is known for its resonance and attractive sound.
In Russia, church bells are usually casted with a special mix of copper and tin, often added with silver, to create their distinctive sonority and resonance, early mastered in Russian Christian history.
Therefore, bell metal as an alloy contains copper and tin.
Hence, option A is correct.

Note- This alloy's crystal lattice structure is capable of absorbing high impact energies, like from a bell clapper without any distortion as is the case when the bell is struck. This results in a resonant sound in a complex nodal system which causes the bell to vibrate strongly.