Rusting of iron can be prevented by methods like painting, oiling, greasing, galvanising, chrome plating, anodising, or making alloys. Galvanisation protects iron even if the zinc coating is broken because zinc acts as a sacrificial anode, corroding instead of iron.

Iron rusts when exposed to moist air for a long time, forming a brown flaky substance called rust. In an experimental setup, iron nails rust in a test tube exposed to both air and water (Test Tube A), while they ...

Copper loses its shiny brown surface and gains a green coat when exposed to moist carbon dioxide, and the green substance formed is basic copper carbonate.

In electrolytic refining, the impure metal is made the anode, and a thin strip of pure metal is made the cathode. A metal salt solution serves as the electrolyte.

During electrolytic refining, the impure metal at the anode dissolves into the electrolyte, while an equivalent amount of pure metal is deposited on the cathode. Soluble impurities go into the solution, and insoluble impurities settle as anode mud at the ...

Silver articles turn black when they react with sulphur in the air, forming a coating of silver sulphide.