In Millikan’s experiment, the oil droplets acquire one or more negative charges by combining with the negative charges that are
produced from the ionization of air by X rays. By measuring the charges on the oil droplets, he calculated the charge on a single electron as −1.60×10−19 C. The charge on any negatively charged oil droplet is always a whole-number multiple of the fundamental charge of a single electron.If Millikan was measuring the charge on an oil droplet with 4 negatively charged electrons on it, what charge would he have measured on the droplet?
-6.4x10⁻¹⁹ C
The fundamental charge of an electron is -1.60x10⁻¹⁹ C, meaning that each electron has its specific charge. In a sample containing multiple electrons, the total charge will be a multiple of the fundamental charge, based on the electron count. Therefore, for an oil droplet with four electrons, the total charge equates to four times the elementary charge:
4*(-1.60x10⁻¹⁹) C = -6.4x10⁻¹⁹ C