Torch cut drp chemical name & process

Answer:if we have to make a duplicate rice puller from a copper coin. The coin attratcs rice from 2 to 3 inch. IF we bring a lighted torch with glass removed the bulb goes off If we put a copper wire on the coin for 20 sec n removes it, the wire becomeslike itThese all is made with some CHEMICALS what is that chemical n what is the procidure