Question

A plastic bag rubbed with cotton wool acquired a positive charge. This happened because:
(a) the plastic acquired extra protons from the cotton.
(b) the plastic acquired extra protons on rubbing.
(c) new protons were created on the plastic while rubbing.
(d) the plastic lost electrons to the cotton during rubbing.

Answer 1

(d) the plastic lost electrons to the cotton during rubbing

A plastic bag rubbed with cotton wool acquires a positive charge because the plastic loses electrons to the cotton during the rubbing and becomes less negative.