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 ...

THE connection between dentistry and chemistry is a two-fold one. The practical dental surgeon is a worker in metals; he has to prepare amalgams for stoppings and carry out a multitude of similar ...

Three colorless solutions are combined into a large beaker and the mixture becomes amber, then blue-black, and then colorless again. This sequence of color changes will repeat with a period of ...