Because molten silver contains mercury in presence of air. Since mercury is a weak metal hence it does support for making sharp castings.
Silver is the best conductor of electricity can you say why electric wires are not made up of silver?
(Could you please check my answer)
Ans: Though silver is a good conductor of heat but it is not used in making electric wire as it is very expensive .silver is a noble metal and it is used in making jewelry it is also used in electroplating and in making high Value coins that is why silver is not used in making electric wires
Why gold and silver are used to make ornaments?