Chemistry - Atomic Structure Question with Solution | TestHub

Question Explanation: Identifying experimental sources of error in Millikan's oil drop experiment.

Concept: Sources of error in Millikan's Experiment.

Solution: The charge $q$ is calculated using the formula:

$$q=\frac{6\pi \eta r(v_1+v_2)}{E}$$

Evaporation: Changes the mass and radius of the drop during the experiment, leading to inconsistent force balancing.

Brownian Motion: Causes random fluctuations in the movement of very small drops, making it difficult to measure precise terminal velocities.

Viscosity ($\eta$): The calculation of the drop's radius and charge depends directly on the value of the viscosity of air; an incorrect value leads to a systematic error.

Ionization: This is a necessary part of the experiment to charge the drops, not an error.