Question

why gold and silver are used in making coins

Answer 1

Coins were used for monetary transactions. To trade goods, it was necessary to have a uniform and compact currency which could not be easily produced illegally. During the period when law was not well developed and uniform among the states, people had to choose something that was compact and of high and equal value for everyone, and metals like gold and silver were perfectly fit for that because they were rare and hence had a high value. Also, coins of gold and silver were compact and portable.

Answer 2

Gold and silver are used to make coins because they have the characteristics of malleability and ductility. They can be easily drawn in the form of wires or in the form of sheets.
And secondly, they are shiny in nature which helps the customer to get attract.