Which of the following charge is not possible to occur?

Question

a) 1.6 x 10^-19C

b) 3.2 x 10^-19C

c) 3.6 x 10^-17C

d) 3.6 x 10^-22C

I'm getting D as the answer, is it correct?

Answer 1

Charge only exists in integer multiples of the fundamental charge, because the charge needs to come from an integer number of electrons and protons which both have about the fundamental charge. For an electron the fundamental charge is 1.6⋅10^-19 C. A positive charge would come from the abscence of electrons so, a) would be 1 electron (1.6⋅10^-19 C/1.6⋅10^-19 C) removed, b) would be 2 electrons (3.2⋅10^-19 C/1.6⋅10^-19 C) removed, c) would be 225 electrons (3.6⋅10^-17 C/1.6⋅10^-19 C) removed, d) is much smaller than the fundamental charge. d) looks like charge that can't exist.