Separation of Substances :- The substances to be separated may be particles of different sizes or materials. These may be in any three states of matter i.e., solid, liquid or gas.
Methods of Separation:-
1. Handpicking :- The method of handpicking can be used for separating slightly larger sized impurities like the pieces of dirt, stone, and husk from wheat, rice or pulses.
2. Threshing :- The process that is used to separate grain from stalks etc. is Threshing. In this process, the stalks are beaten to free the grain seeds. Sometimes, threshing is done with the help of bullocks. Machines are also used to thresh large quantities of grain.
3. Winnowing :- Winnowing is used to separate heavier and lighter components of a mixture by wind or by blowing air. This method is commonly used by farmers to separate lighter husk particles from heavier seeds of grain.
4. Sieving:- Sieving is used when components of a mixture have different sizes. For example:- Sieving allows the fine flour particles to pass through the holes of the sieve while the bigger impurities remain on the sieve.
5. Sedimentation, Decantation , Filtration :- When the heavier component in a mixture settles after water is added to it, this process is called sedimentation. When the water (along with the dust) is removed, the process is called decantation.
For example, oil and water from their mixture can be separated by this process. Filtration is a way to separate solid particles from a liquid using a filter, like a sieve or filter paper, that lets the liquid pass through but traps the solids.
6. Evaporation:- The process of conversion of water into its vapour is called evaporation. The process of evaporation takes place continuously wherever water is present.
Condensation:- The process of conversion of water vapour into its liquid form is called condensation.
Solution:– Solution is prepared by dissolving a substance in a liquid.
Saturated Solution:- A solution is said to be saturated if it cannot dissolve more of the substance in it.