In a series of oil-drop experiments, the charges measured on...

In a series of oil-drop experiments, the charges measured on the oil drops were $-4.80 \times 10^{-19} \mathrm{C},-6.40 \times$ $10^{-19} \mathrm{C},-9.60 \times 10^{-19} \mathrm{C}$, and $-1.28 \times 10^{-18} \mathrm{C}$. What is the smallest difference in charge between any two drops? If this is assumed to be the charge on the electron, how many excess electrons are there on each drop?

Key Concepts

Quantization of Electric Charge

This concept indicates that electric charge exists in discrete amounts rather than a continuous distribution. In experiments like the oil-drop experiment, the differences between measured charges are often integer multiples of a smallest unit, demonstrating that charges come in fixed quantities.

Elementary Charge

The elementary charge is the smallest unit of electric charge, representing the charge carried by a single proton (or the negative of this for an electron). Recognizing that all measured charges are multiples of this unit allows us to determine the number of excess electrons or protons on an object by dividing the total charge by the elementary charge.

Oil-Drop Experiment

This experiment was designed to measure the charge of an electron by balancing gravitational and electric forces on tiny charged oil droplets. It provided crucial evidence for the quantization of electric charge by showing that the charges on the droplets were discrete and related by a common factor, the elementary charge.

Discrete Charge Differences

Analyzing the differences between measured charges on various oil drops can reveal the common increment of charge, which corresponds to the elementary charge. This difference, when consistently observed, confirms that the net charge on the drops stems from an integer number of electrons, supporting the idea that charge is quantized.

Transcript

Please give Ace some feedback