Question

story of a coin (why the iron coins were replaced gradually by copper ,then by brass and finally by steel(currently used in india))

Answer 1

Answer: -

In ancient times iron was used instead of bronze in coins. It is because iron was cheaper to make into coin over bronze.

But iron reacted with oxygen in presence of moisture to form rust. So the markings of the coin which told the value, would slowly disappear with time.

To solve this, copper was used. Copper does not rust easily. It was also cheap. Thus it could be used as coin instead of iron.

Brass started to be used in place of copper because it is harder, stronger, more corrosion resistant and has an attractive gold colour. It also has anti-bacterial properties.

With the prices of brass increasing, steel is also being used in India as it is also corrosion and rust resistant.