The following process can be used to prevent of rusting of iron -
By painting surface of an iron object, air and moisture cannot come in contact with the iron object and hence no rusting takes place,
By applying grease or oil,
By Galvanization , i.e. by depositing a thin layer of zinc metal on iron objects,
By chrome-plating , i.e. Iron is coated with chromium,
By alloying iron with carbon, chromium and nickel to make stainless steel.
Centrifugation: It is a process in which particles are separated from a solution, using centrifugal force, according to their density, size, shape, rotor speed and viscosity of the medium.
During evaporation water changes from a liquid to a gas or vapour
During crystallization, the atoms or molecules, of a solid form, are highly organized into a structure known as a crystal.