Robert Millikan was an American physicist who in 1909 performed a classic experiment involving charged oil drops. Millikan adjusted the voltage applied between two metal plates in order to suspend charged drops in the resulting electric field. For a suspended drop, the electrostatic force directed up exactly balances out the weight of the drop. Millikan ultimately determined the charge on an electron and that charge is quantized. This means that charge comes in increments, discrete amounts, rather than any amount.A NEGATIVELY-charged oil drop is suspended between two plates of opposite charge by an electric field of 402 newtons per coulomb. The drop is determined to have a mass of 3.28 x 10-17 kilograms. What is the charge on the drop? Include units in your answer.