1. Discovery of the Electron (1897):
* Experiment: Thomson conducted experiments with cathode ray tubes. He observed that rays emitted from the cathode were deflected by both electric and magnetic fields, proving they carried a negative charge.
* Significance: This marked the first discovery of a subatomic particle, showing that the atom was not indivisible as previously thought.
2. The Plum Pudding Model (1904):
* Model: Based on his findings, Thomson proposed a model where the atom was a sphere of positively charged matter (like pudding) with negatively charged electrons embedded throughout (like plums).
* Impact: This model challenged the then-prevailing view of the atom as a solid sphere. It introduced the concept of subatomic particles and their arrangement within the atom.
Thomson's work led to several crucial advancements in atomic theory:
* Demolition of the indivisible atom concept: His discovery of the electron proved that atoms were indeed composed of smaller particles.
* Introduction of the concept of subatomic particles: This paved the way for further discoveries and the development of modern atomic models.
* Foundation for future research: Thomson's model, although later replaced, set the stage for Rutherford's groundbreaking gold foil experiment and the development of the nuclear model.
While the "plum pudding model" was eventually proven inaccurate, it was a significant step in understanding the atom's structure. It provided a framework for future research and ultimately paved the way for the modern understanding of the atom as a nucleus surrounded by electrons.
