Question

In Milikan’s experiment, a static electric charge on the oil drops was obtained by shining X-rays. If the static electric charge on the oil drop is –1.282 × 1018C, calculate the number of electrons present on it.

Answer 1

Charge on the oil drop = 1.282 ×1018C
Charge on one electron = 1.6022 × 1019C
∴Number of electrons present on the oil drop
= $\frac{1.282\times10^{-18}C}{1.6022\times10^{-19}C}$
= 0.8001 × 101 = 8.0