Cathode rays have

Options

A. mass only
B. charge only
C. both mass and charge
D. because it is gas

Answer

**Step-by-Step Solution:**

1. **Understanding Cathode Rays**: Cathode rays are streams of electrons observed in vacuum tubes. They were discovered by J.J. Thomson during his experiments with cathode ray tubes.

2. **Charge of Cathode Rays**: Cathode rays consist of negatively charged particles, which are electrons. The charge of an electron is approximately \( -1.6 \times 10^{-19} \) coulombs.

3. **Mass of Cathode Rays**: Electrons, which make up cathode rays, have a mass of approximately \( 9.1 \times 10^{-31} \) kilograms. This indicates that cathode rays do indeed have mass.

4. **Conclusion**: Since cathode rays are composed of electrons, they possess both mass and charge. Therefore, the correct statement regarding cathode rays is that they have both mass and charge.

5. **Final Answer**: Cathode rays have both mass and charge.

---