Aparticle could have a charge of
(1) 0.8 × 10^−19 c (3) 3.2 × 10^−19 c
(2) 1.2 × 10^−19 c (4) 4.1 × 10^−19 c

The correct answer is 
 (3) 3.2 × 10^−19 C

In fact, electric charge is quantized: the elementary charge is the charge of the electron, , and every particle can only have an electric charge which is an integer multiple of this value. Of the options listed above, only option (3) is an integer multiple of the elementary charge: in fact, it corresponds to 2 times the electron charge: