R.A.Millikan
I determine the charge on the electron.
II found the value of charge on the electron is `1.6xx10^19 C`.

Options

A. Only I
B. Only II
C. Both (1) and (2)
D. None of the above

Answer

To solve the question regarding R.A. Millikan's contributions to the determination of the charge on the electron, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Identify R.A. Millikan's Contribution**:
R.A. Millikan is known for his significant work in determining the charge of the electron. This was accomplished through his famous oil drop experiment conducted in 1909.

**Hint**: Remember the key experiment associated with Millikan's work.

2. **Understand the Oil Drop Experiment**:
In the oil drop experiment, Millikan measured the charge on tiny oil droplets that were suspended in an electric field. By adjusting the electric field, he was able to balance the gravitational force acting on the droplets with the electric force, allowing him to calculate the charge on each droplet.

**Hint**: Focus on how the experiment was set up and what forces were involved.

3. **Determine the Charge Value**:
Through his experiments, Millikan found that the charge of the electron is approximately \(1.6 \times 10^{-19}\) coulombs. This value is fundamental in physics and chemistry as it represents the smallest unit of charge.

**Hint**: Remember the numerical value and its scientific notation.

4. **Conclusion**:
Both statements regarding Millikan's work are correct:
- He determined the charge on the electron.
- He found the value of the charge on the electron to be \(1.6 \times 10^{-19}\) C.

**Hint**: Verify if both statements align with the historical context of Millikan's findings.

### Final Answer:
Both statements about R.A. Millikan are true. He determined the charge on the electron and found its value to be \(1.6 \times 10^{-19}\) C.