The smallest unit of charge is − 1.6 × 10 − 19 C, which is the charge in coulombs of a single electron. Robert Millikan was able to measure the charge on small droplets of oil by suspending them between a pair of electrically charged plates. Which of the values are possible charges of those oil droplets?

Only multiples like -3.2 × 10⁻¹⁹C, - 4.8 × 10⁻¹⁹C and - 8.0 × 10⁻¹⁹C are feasible values of the charges on the oil droplets among the options provided.

Explanation:

The Milikan's oil drop experiment was important and revolutionary beacause it discovered that the charge of an electron, which is equal to e = −1.6 × 10⁻¹⁹ C, is a fundamental unit of charge, and that all electric charges are made up of groups of electrons.

Hence, the possible charges on the oil droplets for the experiment were all 'quantized' and all electric charges must be multiples of the charge of an electron.

Meaning that the charges on the oil droplets can take on value of ne = n (1.6 × 10⁻¹⁹)C where n takes on whole, natural numbers such as (1, 2, 3, 4,......, n).

So only multiples like -3.2 × 10⁻¹⁹C, - 4.8 × 10⁻¹⁹C and - 8.0 × 10⁻¹⁹C are feasible values of the charges of the oil droplets.