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

Answer

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. **Identify the Scientist**: The question refers to J.J. Thomson, a prominent scientist known for his work in physics and chemistry.

**Hint**: Remember the key figures in the discovery of electrons.

2. **Determine the Year of Discovery**: J.J. Thomson discovered the electron in the year 1897.

**Hint**: Knowing the timeline of scientific discoveries can help contextualize the findings.

3. **Identify the Equipment Used**: Thomson conducted experiments using a specific piece of equipment. He used cathode ray tubes in his experiments.

**Hint**: Think about the types of equipment that are commonly associated with experiments in atomic physics.

4. **Understand the Experiment**: The experiments with cathode ray tubes led to the conclusion that all atoms contain tiny negatively charged subatomic particles, which are now known as electrons.

**Hint**: Consider what the purpose of cathode ray tubes is in the study of atomic structure.

5. **Conclude the Answer**: Based on the information gathered, the correct answer to the question is that J.J. Thomson used cathode ray tubes to discover electrons.

**Hint**: Summarize your findings to ensure clarity in your answer.

### Final Answer:
J.J. Thomson discovered electrons using **cathode ray tubes**.