Electric charge — Describe

Describe an experiment to produce electrostatic charge by friction and one to detect the charge produced.

Rubbing two insulating materials together (e.g. a polythene rod with a cloth) transfers electrons between their surfaces, leaving both objects charged (one positive, one negative) - this is charging by friction. To detect the charge, bring the charged rod close to small pieces of paper or a suspended charged ball; the paper is attracted to the rod, or the ball is attracted/repelled, showing that charge is present. A gold-leaf electroscope can also be used: its leaf diverges when a charged object is brought near or touched to its cap.