Question

What are the cathode rays composed of?

• A. Only mass
• B. Only charge
• C. Neither mass nor charge
• D. Both mass and charge

Answer 1

The correct option is D Both mass and charge

J. J. Thomson showed the cathode rays were composed of a previously unknown negatively charged particles, which was later named the electrons. They were considered negative based on the deflection in the electric field. When the positive charge was brought near cathode rays, they were attracted and when the negative charge was brought nearer, the cathode rays got deflected. The rays were also able to move a tiny wheel that was placed in their path which proves the rays have particles and therefore mass.