Which subatomic particle was discovered by researchers working with cathode ray tubes?

• A. Electron
• B. Neutron
• C. Positron
• D. Proton

Answer: (A)

Verified step by step guidance

1. Understand the context: Cathode ray tubes were used in early experiments to study the nature of electric discharge in gases at low pressure.
2. Recall that cathode rays are streams of particles emitted from the cathode (negative electrode) in these tubes.
3. Recognize that J.J. Thomson conducted experiments with cathode ray tubes and discovered that these rays were composed of negatively charged particles smaller than atoms.
4. Identify these particles as electrons, which are subatomic particles with a negative charge and very small mass compared to protons and neutrons.
5. Conclude that the subatomic particle discovered using cathode ray tubes is the electron.