Thomson

Definition

J.J. Thomson was a physicist who discovered the electron and proposed the 'plum pudding' model of the atom. His work laid the foundation for understanding atomic structure and electron behavior in atoms.

5 Must Know Facts For Your Next Test

1. J.J. Thomson discovered the electron in 1897 using a cathode ray tube experiment.
2. He proposed the 'plum pudding' model of the atom, where electrons were embedded in a positively charged 'pudding'.
3. Thomson's discovery showed that atoms are divisible, contradicting Dalton's earlier atomic theory.
4. His work earned him the Nobel Prize in Physics in 1906 for his investigations on the conduction of electricity by gases.
5. Thomson's findings led to further developments in atomic theory, eventually leading to the Rutherford model.

Review Questions

• What particle did J.J. Thomson discover and how?
• Describe Thomson's 'plum pudding' model of the atom.
• How did J.J. Thomson’s discovery change previous atomic theories?

Related terms

Electron: A subatomic particle with a negative charge found outside the nucleus of an atom.

Plum Pudding Model: Thomson's early model of atomic structure where electrons are dispersed within a positively charged sphere.

Cathode Ray Tube: The device used by J.J. Thomson to discover electrons, which produces streams of electrons when high voltage is applied.