Cathode rays were discovered by

Options

A. Maxwell Clerk James
B. Heinrich Hertz
C. William Crookes
D. J.J. Thomson

Answer

**Step-by-Step Solution:**

1. **Understanding Cathode Rays**: Cathode rays are streams of electrons observed in vacuum tubes. They are produced when an electric current passes through a gas at low pressure.

2. **Historical Context**: The discovery of cathode rays dates back to the late 19th century when scientists were experimenting with electricity and gases.

3. **Key Figure**: The discovery of cathode rays is primarily attributed to William Crookes, an English chemist and physicist.

4. **Crookes' Experiment**: Crookes conducted experiments using a vacuum tube, which led to the identification of cathode rays as streams of negatively charged particles (electrons).

5. **Significance**: Crookes' work not only led to the understanding of cathode rays but also contributed to the discovery of new elements and the understanding of atomic structure.

6. **Conclusion**: Therefore, the correct answer to the question "Who discovered cathode rays?" is William Crookes.

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