Charging materials by friction
3 marks · EasyA student rubs a polythene rod with a dry cloth.
State what happens to the charge on the polythene rod after rubbing.
State which particle moves to create the charge.
Does the polythene rod gain or lose electrons? Explain briefly.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) It becomes negatively charged.
(b) Electrons
(c) The rod gains electrons; these move from the cloth to the rod.
Common mistakes: Saying protons move; Saying rod loses electrons
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States that polythene rod becomes negatively charged.
B1 (b) · 1 mark · Correctly identifies electrons as the particle that moves.
B1 (c) · 1 mark · States rod gains electrons, or that electrons move onto the rod.
Worked solution
(a) The polythene rod becomes negatively charged after rubbing.
(b) It is electrons that move.
(c) The rod gains electrons from the cloth.