Electroplating

Electroplating is a process where the surface of one metal is coated with a layer of a different metal
The metal being used to coat is a less reactive metal than the one it is covering
The anode is made from the pure metal used to coat
The cathode is the object to be electroplated
The electrolyte is an aqueous solution of a soluble salt of the pure metal at the anode

A piece of iron being electroplated with tin. The electrolyte is tin(II) chloride, a water-soluble salt of tin

Uses of electroplating

Electroplating is done to make metals more resistant to corrosion or damage, e.g: chromium and nickel plating
It is also done to improve the appearance of metals, e.g: silver plating cutlery

Conductors & insulators

Conductors

Conductors of electricity allow electrical charge to pass through them easily
Conductors can be:
- Solids such as metals or graphite
- Liquids such as molten lead bromide or molten metals
- Solutions such as sodium chloride solution
Copper is used extensively in electrical wiring as it is an excellent conductor and is malleable and easy to work with
Aluminium is used in overhead cables which are reinforced with a steel core
The steel core provides extra strength and prevents the cable from breaking under its own weight
Although not as good a conductor as copper, it is less dense and cheaper than copper

Insulators

Insulators resist the flow of electricity and do not conduct
Most insulators are solids of plastic, rubber or ceramic
Plastics are used as insulators and are placed around electrical wiring and for some tool and machine handles
Ceramics are used in very high voltage lines where contact between the power line and the metal of the pylon would be dangerous