Which of the following pieces of equipment was used by J.J. Thomson to find electrons?

Options

A. an electron microscope
B. a magnifying glass
C. a cathode-ray tube
D. a telescope

Explanation

To solve the question "Which of the following pieces of equipment was used by J.J. Thomson to find electrons?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand J.J. Thomson's Contribution**:
- J.J. Thomson was a scientist who made significant contributions to atomic theory. He is best known for discovering the electron.

2. **Identify the Model Proposed by Thomson**:
- Thomson proposed the "Plum-Pudding Model" of the atom. This model suggested that atoms are composed of a positively charged "pudding" with negatively charged "plums" (electrons) embedded within it.

3. **Determine the Equipment Used**:
- To discover the electron, J.J. Thomson conducted experiments using a specific piece of equipment. He used a device that allowed him to observe the behavior of charged particles.

4. **Recognize the Equipment**:
- The equipment that J.J. Thomson used for his experiments was the **cathode ray tube**. This device enabled him to observe cathode rays, which are streams of electrons.

5. **Conclusion**:
- Therefore, the correct answer to the question is that J.J. Thomson used the **cathode ray tube** to find electrons.

### Final Answer:
The equipment used by J.J. Thomson to find electrons was the **cathode ray tube**.

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