Which physicist is credited with discovering the electron as a subatomic particle through cathode ray tube experiments?

Introduction / Context:
The discovery of the electron was a turning point in physics and chemistry because it showed that atoms are not indivisible but contain smaller charged particles. This discovery helped scientists develop new models of the atom and opened the door to modern electronics. The question asks you to recall which physicist identified the electron through experiments with cathode rays, a standard fact in atomic structure chapters and general science sections.

Given Data / Assumptions:

• The particle in question is the electron, a negatively charged subatomic particle.
• The discovery involved cathode ray tube experiments.
• The options list scientists and inventors from nuclear physics, microelectronics and design.
• Only one name is correctly associated with discovering the electron.

Concept / Approach:
J. J. Thomson, an English physicist, is credited with discovering the electron in 1897. By studying cathode rays, he showed that they consisted of negatively charged particles with a much smaller mass than atoms. This led to the idea that atoms have internal structure. Enrico Fermi worked on nuclear physics and the first nuclear reactor, Robert Noyce co invented the integrated circuit, and James Dyson is known for vacuum cleaners and engineering design. None of these individuals discovered the electron, so J. J. Thomson is the correct answer in standard GK and science references.

Step-by-Step Solution:
Step 1: Note the key details: cathode ray tubes and the discovery of a negatively charged subatomic particle.Step 2: Recall that J. J. Thomson experiments led to the identification of the electron.Step 3: Locate J.J.Thomson as option C in the list.Step 4: Recognise that Enrico Fermi is associated with nuclear reactors and beta decay, not with electron discovery.Step 5: Recognise that Robert Noyce co invented the integrated circuit decades after electrons were already known.Step 6: Recognise that James Dyson is an industrial designer of modern appliances, unrelated to particle discovery.Step 7: Select J.J.Thomson as the correct answer.

Verification / Alternative check:
Atomic structure chapters in physics and chemistry textbooks nearly always begin by naming J. J. Thomson as the discoverer of the electron and describing his cathode ray experiments. They then describe his atomic model and later developments. Fermi, Noyce and Dyson appear in entirely different contexts, such as nuclear physics, integrated circuits and consumer product design. This clear separation ensures that J. J. Thomson is the correct choice for questions about the electron discovery.

Why Other Options Are Wrong:
Enrico Fermi contributions lie in nuclear physics and the development of the first controlled nuclear chain reaction, not in the original discovery of the electron. Robert Noyce is famous for microelectronics and the integrated circuit, which depend on electron behaviour but came long after the electron was known. James Dyson designs household appliances and is not a historical figure in basic physics. These facts make options A, B and D incorrect for this question.

Common Pitfalls:
Because Fermi and Noyce are associated with advanced physics and electronics, some candidates might mistakenly assume they discovered the electron. Others may not pay attention to the cathode ray detail in the question. To avoid such errors, associate cathode rays and early atomic models with J. J. Thomson, and remember that Fermi and Noyce came later in the timeline of physics and electronics. This mental ordering of discoveries helps you answer many exam questions on atomic theory correctly.

Final Answer:
The electron as a subatomic particle was discovered by J. J. Thomson.