There's no such thing as alchemy—magically changing common chemical elements into rare and valuable ones—but electroplating is possibly the next best thing. The idea is to use electricity to coat a relatively mundane metal, such as copper, with a thin layer of another, more precious metal, such as gold or silver. Electroplating has lots of other uses, besides making cheap metals look expensive. We can use it to make things rust-resistant, for example, to produce a variety of useful alloys like brass and bronze, and even to make plastic look like metal.
So what is electroplating ?
Electroplating involves passing an electric current through a solution called an electrolyte. This is done by dipping two terminals called electrodes into the electrolyte and connecting them into a circuit with a battery or other power supply. The electrodes and electrolyte are made from carefully chosen elements or compounds. When the electricity flows through the circuit they make, the electrolyte splits up and some of the metal atoms it contains are deposited in a thin layer on top of one of the electrodes—it becomes electroplated. All kinds of metals can be plated in this way, including gold, silver, tin, zinc, copper, cadmium, chromium, nickel, platinum, and lead.
Why use electroplating
Electroplating is generally done for two quite different reasons. Metals such as gold and silver are plated for decoration: it's cheaper to have gold- or silver-plated jewelry than solid items made from these heavy, expensive, precious substances. Metals such as tin and zinc (which aren't especially attractive to look at) are plated to give them a protective outer later.