Here's how it unfolded:
* Cathode Ray Tubes: Thomson was studying the behavior of cathode rays, which are beams of electrons emitted from a negatively charged electrode in a vacuum tube. He observed that these rays could be deflected by both electric and magnetic fields.
* Measuring the Charge-to-Mass Ratio: Thomson was able to measure the ratio of the charge of the particles in the cathode rays to their mass. This ratio was found to be much smaller than the charge-to-mass ratio of any known ion, suggesting that the particles in the cathode rays were much lighter than atoms.
* Conclusion: Based on these observations, Thomson proposed that the particles in the cathode rays were fundamental particles that he named "electrons." He concluded that atoms were not the smallest particles of matter but were instead composed of smaller, negatively charged particles called electrons embedded within a positively charged sphere.
This discovery was groundbreaking because it challenged the long-held belief that atoms were indivisible and the fundamental building blocks of matter. It paved the way for further research that led to the discovery of the nucleus and protons, ultimately leading to our modern understanding of the atom.
