Metal on the solution change their characteristic like magnet, but metal solution more like electric current. Like an electric, metal solution have pole, all metal have positive pole on the solution, but some metal may more positive than the others. If there are two metals on the solution, then metal that have less positive charge will act as negative pole and metal with more positive charge will act as positive pole.
The metal solution is called with positive ion, positive ion will move freely on the solution. If there are electrodes that charge with electric current with certain pole, those ion will go to the opposite pole. Positive ion will go to the negative electrode, and negative ion will go to the positive electrode. If the electrode can attract and stick that ion so metal ion will stick to the electrode and coated the electrode.
Electroplating is the deposition of a metallic coating by putting a negative charge on an object and exposing it to a solution containing a metal salt. The more positively charge metal ions in the metal solution are attracted to the object and reduced to metallic from upon it. Some metal can’t stick strongly to an electrode and after the electric charge is loosed those metal coated on the electrode will easily to clean. For certain metal can stick strongly to certain electrode, and those ion will coated the electrode or plating the metal like on Chrome Electroplating.
