Define the term hand picking.

Hint: Separation of substances or mixtures can be followed through some common processes like threshing, hand picking, winnowing, sieving, distillation, evaporation, filtration etc. Hand picking is one of the methods.

Complete step by step answer: It is a very old and traditional separation technique. It is one of the methods that is used in everyone’s daily life. One of the common examples are removing stones and other impurities from rice and then washing it by your mother. It is a very simple technique. The method in which impurities or stones etc can be separated by just picking them out with the help of hand is known as hand picking. As the name suggests, we use the hand to pick the impurities from the mixture or substances. It has advantages and disadvantages too.
Advantages:
-It does not require any large or complex type of machinery to do the process of separation of substances or mixtures.
-It also takes less time but it depends on the quantity we take for the process.
Disadvantages:
-It is not feasible for large quantities of substances and mixtures for separation.
-This process can only be possible if the substances are different in size and can be identified like colour variation, shape, smell etc.
Examples:
-Separation of mixture of pulses and rice. (on the basis of colour)
-Separation of rotten vegetables from the fresh ones. (on the basis of odour)

Note: This method is very ancient but it is followed even in the present life. Many heterogeneous mixtures that are enough in size can be separated simply through this method of hand picking. It can be used frequently in our daily life.