Separating Materials Using Static Electricity

Aim:

The aim of this science experiment is to conduct a simple experiment to separate different materials in a mixture using static electricity.

Materials required for the experiment:

  1. A plastic comb.
  2. A woolen cloth.
  3. A tray or a clean tabletop.
  4. Some pepper.
  5. Some sugar.
  6. Some salt.

Procedure:

  1. Keep the pepper, sugar and salt in separate heaps equidistant from each other in the tray or on the tabletop.
  2. Rub the comb on the woollen cloth brusquely.
  3. Hold the comb above the tray or tabletop. Observe which materials are attracted towards it and whether it attracts from all distances equally or not.
  4. Next, mix all three materials together thoroughly and put them in a heap at the centre of the tray or tabletop.
  5. Bring the comb above the heap. Observe which ingredients are pulled out of the heap by the comb.

Scientific explanation:

On rubbing the comb with the woollen cloth, it acquires some charge which may be positive or negative. Pepper, sugar and salt will each have a similar charge, which is positive or negative. The ingredients which have opposite charge to the charge of the comb will be attracted towards it and the ingredients with the same charge will be repelled. According to the strength of the charge on the comb, the distances over which it can attract or repel also vary.