A sacrificial anode, or sacrificial rod, is a metallic anode used in an electrochemical process where it is intended to be dissolved to protect other metallic components. Diagram of a zinc anode in a Daniells cell. ...

In laymen's terms, it's a piece of readily corrodible metal attached (by either an electrically conductive solid or liquid) to the metal you wish to protect. This piece of metal corrodes first, and generally must dissolve nearly completely before the protected metal will corrode (hence the term "sacrificial").

More scientifically, a sacrificial anode can be defined as a metal that is more easily oxidized than the protected metal. Electrons are stripped from the anode and conducted to the protected metal, which, for this reason, is forced to become the cathode. As a result, the protected metal is prevented from corroding. For example, a piece of zinc and iron is put together.When they touch with oxygen,znic and oxygen will loss electron at the same time.However,iron is less reactive than zinc, it tend to aborb the electron zinc loss relatively.Therefore, iron is a neutral atom and znic is a cation and react with oxygen,and iron is "safe" until all znic are rust. Diagram of a copper cathode in a Daniells cell. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... Properties The electron is a lightweight fundamental subatomic particle that carries a negative electric charge. ... A cation is an ion with positive charge. ...

One example is the galvanic anode used in a cathodic protection system, where the intended purpose is to prevent corrosion of the protected metal (such as a ship's hull, an oil pipeline, or a hot-water heater's tank) by being more electronegative than the desired metal. Commonly used metals for such protective purposes are zinc, aluminum and magnesium. A galvanic anode, also known as a sacrificial anode, is used to protect metals from galvanic corrosion, by the use of a metal electrode which is itself consumed instead in an anodic oxidation reaction. ... Aluminium anodes mounted on a steel jacket structure Cathodic protection (CP) is a technique to control the corrosion of a metal surface by making that surface the cathode of an electrochemical cell. ... A trio of propane water heaters. ... Electronegativity is a measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ...

Another example is the anode in an electroplating process, whereby the metal from the anode replaces the metal depleted from the plating solution as it is deposited on the cathode. Electroplating is the coating of an electrically conductive item with a layer of metal using electrical current. ...