Charge Quantization on Oil Droplets

Steps:

• The charge on oil droplets is quantized as q = n e, where e = 1.6 × 10^{-19} C and n is a non-negative integer.
• For zero charge, n = 0, which is possible.
• Divide each option by e to check if n is an integer: A: 0 / e = 0; B: 1.0 × 10^{-19} / e = 0.625; C: 4.8 × 10^{-19} / e = 3; D: 8.0 × 10^{-19} / e = 5.
• Only B yields a non-integer n, so it is impossible.

Why B is correct:

• B equals 0.625 e, violating the quantization rule from Millikan's experiment where charge must be an integer multiple of e.

Why the others are wrong:

• A is 0 e, allowed for uncharged droplets.
• C is 3 e, a valid multiple.
• D is 5 e, a valid multiple.

Final answer: B