A polar molecule will have a partially positively charged end and a partially negatively charged end. The negatively charged end of the polar molecule will get attracted to the positively charged metal plate and the positively charged end of the polar molecule will get attracted to the negatively charged metal plate. This is based on Coulomb’s law of attraction of opposite charges.
If you want to separate black grapes from the mixture of black and green grapes, then you will simply pick black grapes using your hands from the mixture. In this way you are actually using handpicking separation method.
