Hint: Pebbles are bigger in size and sand particles are small in size. Various separation techniques are used to separate particles from mixtures or compounds.
Complete step by step answer: -All substances are not present in their pure form in nature. Most of the substances are present in the form of mixtures. We can separate useful components of the mixtures by using various methods of separation. Handpicking is one of the methods of separation. It is a very old separation technique. -Yes, pebbles can be easily separated from sand particles using handpicking. - It is a process in which the bigger particles can be separated easily just by picking them out with the help of the hand. It is one of the various methods which are carried out in dry conditions. -Other examples of handpicking separation methods are: 1.Separating the mixture of chilies and ladyfinger 2.Separating stones from rice, pulses and wheat 3.Separating rotten potatoes from fresh ones 4.Separating different kinds of vegetables from the mixture of vegetables. 5.This method has various advantages as well such as: 6.It is very simple and easy method of separation 7.It doesn’t require any kind of equipment to proceed. 8.It takes very less time when performed for a small quantity of mixture. 9.It doesn’t require any kind of preparation.
Hence, option A is correct.
Note: This technique has some limitations as well. We can’t separate all heterogeneous mixtures by handpicking and it is a very time-consuming process if the quantity of the mixture is large. Other methods of separation include threshing, filtration, distillation, magnetic separation, etc. depending upon the type of mixture to be separated