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 modern atomic theory and greatly influenced our understanding of electric charge.

5 Must Know Facts For Your Next Test

1. J.J. Thomson discovered the electron in 1897 using cathode ray tube experiments.
2. Thomson measured the charge-to-mass ratio (e/m) of electrons, which was crucial for identifying them as subatomic particles.
3. He received the Nobel Prize in Physics in 1906 for his work on the conduction of electricity in gases.
4. Thomson’s plum pudding model suggested that atoms were composed of electrons scattered within a positively charged 'soup'.
5. His discoveries challenged existing theories and paved the way for future models like Rutherford’s nuclear model.

Review Questions

• What significant particle did J.J. Thomson discover, and how?
• Explain Thomson's contribution to measuring the charge-to-mass ratio of an electron.
• Describe how Thomson's plum pudding model envisioned atomic structure.

Related terms

Electron: A subatomic particle with a negative charge, discovered by J.J. Thomson.

Cathode Ray Tube: An experimental apparatus used by J.J. Thomson to discover electrons by observing deflected rays.

Plum Pudding Model: An early atomic model proposed by J.J. Thomson where electrons were embedded in a positively charged 'pudding'.