Separation of Substances Notes

• The process of pouring out the clear upper liquid without disturbing the sediments is called decantation.

e.g.: Sand and water can be separated by leaving its mixture undisturbed for some time by sedimentation and decantation.

• The process by which two substances (an insoluble solid and a liquid) are separated by passing the mixture through a filtering device is called filtration.

• Filtration is commonly used in our homes.
• For instance, after preparing tea we filter out the tea leaves using a strainer.

Filtration is also Done:

• The process of conversion of liquid into gaseous state is called evaporation.

• In this method, the mixture is heated.
• The liquid part of the mixture evaporates and escapes, leaving the solid part behind.

• The above given picture shows the evaporation of water in the sea due to heat.