Some folks suggested copper pennies (old ones minted 1981 and earlier – the new ones are zinc with copper plating and won’t help much). [tangentsoft] built a jig to test six LM317 regulators ...

A copper penny appears to turn to silver after heating in an evaporating dish with a mixture. The penny then appears to turn to gold when heated in a flame. Heat causes a fusion of zinc and copper to ...

A copper penny is heated and suspended above the surface of acetone in a beaker. The copper demonstrates heterogenous catalysis in the combustion of acetone to carbon dioxide and water. This exotherm ...